FNIP2 and neoplasm: Reintroducing FNIP2-WT conversely blocked colony formation of the FNIP-depleted UOK-257-2 cells whereas reintroducing the FNIP2-3A mutant further suppressed cell growth, suggesting a tumor suppressive role of FNIP2 and a contribution of β-TRCP in promoting renal cancer cell proliferation (Figure 7C).