PTPN1 and renal carcinoma: In renal cancer cells, MIC-1 suppresses growth and migration by inhibiting PTP1B-dependent Src/Ras/Raf/ERK signaling, enhances the pro-apoptotic Bax/Bcl-2 ratio in xenograft models while inhibiting ERK phosphorylation (Figure 5), establishing a mechanistic bridge between upstream phosphatase targeting and downstream caspase-driven apoptosis [34].