You may cancel your Account at any time. You may cease use of a Subscription at any time or, if you choose, you may request that Valve terminate your access to a Subscription.

“You may cancel your Account at any time. You may cease use of a Subscription at any time or, if you choose, you may request that we terminate your access to a Subscription. However, Subscriptions are not transferable, and even if your access to a Subscription for a particular game or application is terminated, the original activation key will not be able to be registered to any other account, even if the game or application was purchased in a retail store. Access to Subscriptions purchased as a part of a pack or bundle cannot be terminated individually, termination of access to one game within the bundle will result in termination of access to all games purchased in the pack will be removed from the account.”