RAC1 and autism: The most salient results included: 1) upregulation of RAC1 in BA9 and the vermis of adults with autism, and in BA9 only among children with autism; 2) upregulation of APP120 and 88 kDa species in BA9 of children with autism and downregulation of APP 120 kDa in the vermis of adults with autism; 3) upregulation of STEP 46 kDa in BA9 and downregulation of STEP 66 kDa, 33 kDa, and 27 kDa in the vermis of adults with autism; 4) downregulation of STEP 61 kDa in BA9 of children with autism; and 5) downregulation of homer 1 in BA9 of adults with autism.