Integrated circuits and methods of forming field effect transistors are disclosed. In one aspect, an integrated circuit includes a semiconductor substrate comprising bulk semiconductive material. Electrically insulative material is received within the bulk semiconductive material. Semiconductor material is formed on the insulative material. A field effect transistor is included and comprises a gate, a channel region, and a pair of source/drain regions. In one implementation, one of the source/drain regions is formed in the semiconductor material, and the other of the source/drain regions is formed in the bulk semiconductive material. In one implementation, the electrically insulative material extends from beneath one of the source/drain regions to beneath only a portion of the channel region. Other aspects and implementations, including methodical aspects, are disclosed.