After analyzing samples from patients with primary PCa, xenograft mouse models, transgenic adenocarcinoma mouse prostate (TRAMP) mouse models, and data from the TCGA and MSKCC databases, Gu and co-workers showed that downregulation of the IQGAP1 motif belonging to small G proteins was strongly connected to castration-resistant and advanced PCa. The gene discussed is RAC2; the disease is posterior cortical atrophy.