RAC1 and cancer: Hyperactivation of RAC1 signaling in cancers is caused byrare mutations, overexpression, or dysregulation by RAC1-regulatory proteins, such as GTPase-activating proteins (GAPs),guanine-nucleotide exchange factors (GEFs), and guanine-nucleotide dissociation inhibitors (GDIs) [23].The alternate splicing of RAC1 to produce the constitutively active RAC1B variant, a small GTPase, contributes to the hyperactivation ofRAC1 signaling in certain solid tumors [24].