ADHEREX TECHNOLOGIES INC.

1.	TO SUBSCRIBE FOR SHARES

Fill in and sign Form 1 and Form 2 (if exercising the Over-Subscription Right) on the face hereof on the line "Signature(s)" making certain that your signature corresponds in every particular with your name as it appears on the face of this Certificate. Subscriptions will only be accepted for a whole number of Units.  A bank, trust company, securities dealer or broker which holds Units for more than one beneficial owner may, upon providing evidence satisfactory to Olympia Transfer Services Inc., exercise the Rights evidenced by this Certificate or exchange its Certificate on the same basis as if the beneficial owners were registered holders. Rights certificates for fractional interests shall not be issued and any fractional rights will be eliminated by rounding down to the nearest whole right. If Form 1 is completed so as to exercise some but not all of the Rights represented by this Certificate, the Subscription Rights Holder will be deemed to have waived the unexercised balance of such Rights at the time this Certificate is surrendered, unless the Subscription Rights Holder has provided that the Rights are to be transferred to a third party or are to be retained by the Subscription Rights Holder in the appropriate Forms on this Certificate or otherwise by advising the subscription agent in writing.  Mail or deliver this Certificate with full payment for the subscription price for all Units subscribed for to:

Olympia Transfer Services Inc.

Suite 920, 120 Adelaide St W

Toronto, Ontario M5H 1T1

Attention: Corporate Actions

To be a valid subscription, the appropriate Forms on this Certificate, along with the two (2) anti-money laundering forms attached hereto, must be duly completed, and the required payment must be received by Olympia Transfer Services Inc. at the above offices on or before 5:00 p.m. (New York City Time) on _________, 2011 ("Expiry Date").  For your own protection, if forwarding by mail, it is suggested that overnight courier or registered mail (return receipt requested) be used.  Subject to the satisfaction of conditions herein and in the Prospectus, certificates for the Shares and Warrants as subscribed for will be mailed to you by first class mail at your last recorded address on the records of Adherex Technologies, Inc. (the “Corporation”), or if a different address, the address provided in Form 5 (assuming such form is duly completed and signed with your signature guaranteed), or in the case of a transferee exercising transferred Rights, at the address indicated in Form 3, as soon as practicable.  This Certificate does not entitle the holder to any rights whatsoever as a shareholder of the Corporation.

2.	TO SELL OR TRANSFER RIGHTS

Complete Form 3 on the face hereof, sign, and have your signature guaranteed (i) by a major Canadian Schedule 1 chartered bank, a member of the Securities Transfer Agents Medallion Program (STAMP), a member of the Stock Exchange Medallion Program (SEMP), or a member of the New York Stock Exchange Inc. Medallion Signature Program (MSP) for Canadian holders, or (ii) by an eligible guarantor institution (bank, stock broker, savings & loan association or credit union) with membership in an approved signature guarantee medallion program pursuant to Securities Exchange Act of 1934 Rule 17Ad-15 for U.S. holders, and deliver this Certificate to Olympia Transfer Services, Inc.  Your signature must correspond in every particular with your name as it appears on the face of this Certificate. IF FORM 1 IS PROPERLY COMPLETED, THE SUBSCRIPTION PRICE PAID, AND ALL OTHER REQUIREMENTS TO BE A VALID SUBSCRIPTION ARE SATISFIED, THE TRANSFEREE MAY USE THIS CERTIFICATE FOR SUBSCRIPTION WITHOUT OBTAINING A NEW CERTIFICATE. A sale or transfer should be accompanied by delivery of this Certificate in ample time so that it can be used before the Expiry Date.

3.	PAYMENT OF SUBSCRIPTION PRICE

The total subscription price for the number of Units specified in Form 1 and, if applicable, Form 2, must be paid in full in either Canadian dollars or U.S. dollars, by certified check or bank draft payable to Olympia Transfer Services, Inc. (for the benefit of Adherex Technologies Inc.).  If  the subscriber elects to pay the subscription price in U.S. Dollars, the subscription price shall be calculated based on an exchange rate of [_____] (the US/Canadian currency exchange rate in effect on February XX, 2011).  Funds paid by uncertified check may take at least five (5) business days to clear. Your subscription may not be considered accepted until such check has cleared. Payment can be made by way of wire transfer, contact the subscription agent at ###-###-#### or ***@***.

4.	VALIDITY AND REJECTION OF SUBSCRIPTIONS

All questions as to the validity, form, eligibility (including time of receipt) and acceptance of any subscription will be determined by the Corporation in its sole discretion, whose determination shall be final and binding.  All subscriptions are irrevocable.  The Corporation reserves the right to reject any subscription if such subscription is not in proper form or if the acceptance thereof or the issuance of Shares and Warrants pursuant thereto could be deemed unlawful.  The Corporation also reserves the right to waive any defect with regard to any particular subscription.  Neither the Corporation nor Olympia Transfer Services Inc. will be under any duty to give any notification of any defect of irregularity in such subscriptions nor shall either of them incur any liability for failure to give such notification.

5.	DIVIDE OR COMBINE CERTIFICATES

Certificates may be combined or divided upon surrender of the original certificate(s) by completing and executing Form 4 and delivering this Certificate to Olympia Transfer Services Inc. at the above offices in ample time for the new certificate(s) to be issued before the Expiry Date.  New certificate(s) will be issued in the same name as that reflected on the Certificate(s) surrendered.

6.	DELIVERY TO A DIFFERENT ADDRESS

If you wish for the Shares and Warrants underlying your Rights, to be delivered to an address different from that which is reflected in the records of the Corporation (i.e., the address at which the Rights Certificate was initially received), please enter the alternate address on Form 5, sign and have your signature guaranteed under Form 5.

7.	EVIDENCE OF AUTHORITY

If a form is signed by a trustee, executor, administrator, tutor, curator, guardian, attorney, officer of a corporation or representative capacity, this Certificate should be accompanied by evidence of authority satisfactory to Olympia Transfer Services Inc.