ARHGEF16 is a Rho guanine nucleotide exchange factor that activates small GTPases including RHOG, RAC1, and CDC42 to regulate cell migration and proliferation 1. The protein contains a PDZ-binding domain that mediates interactions with regulatory proteins like Tip-1 2. Mechanistically, ARHGEF16 functions as a downstream effector in multiple signaling pathways. GLI2 transcription factor directly binds the ARHGEF16 promoter to upregulate its expression in glioma cells 3. ARHGEF16 interacts with cytoskeleton-associated protein CKAP5 to promote cell migration and proliferation 3. The HPV16 E6 oncoprotein enhances ARHGEF16-mediated CDC42 activation through the Tip-1 adaptor protein 2. In colon cancer, the FYN tyrosine kinase stabilizes ARHGEF16 protein levels and is required for its proliferative and migratory effects 1. ARHGEF16 demonstrates disease relevance across multiple cancer types. It is highly expressed in colon cancer clinical specimens and promotes both in vitro and in vivo tumor progression 1. Elevated ARHGEF16 expression in gastric cancer is associated with increased metastatic potential 4. In glioblastoma, the GLI2/ARHGEF16/CKAP5 axis drives tumor growth 3. ARHGEF16 was identified as one of six signature genes in an ovarian cancer prognostic model predicting poor outcomes 5. Conversely, reduced ARHGEF16 expression in melanoma cells correlates with potential tumor suppressor function 6.