An apparatus and method for testing a semiconductor device in an AC test regime. The profit optimization system uses an optimization model to optimize profit in a spot market. In an exemplary embodiment, the locking structure is a conductive material added to the surface of the ball pad to provide a nonplanar interface, such as a dome or a step, which interlocks the conductive ball to the ball pad. Each of the block select lines is associated with a respective one of the blocks. The present invention further relates to specific megakaryocyte kinases, designated MKK1, MKK2, and MKK3, and their use as diagnostic and therapeutic agents.