NRP1 and fibrosarcoma: Also along this line, downregulation of NRP1 counteracts the adverse effects of acquired resistance to EGFR, MET, and BRAF (Rat/rapidly accelerated fibrosarcoma, isoform B) inhibitors, as NRP1 upregulates alternative tumor-promoting effector kinases EGFR and IGF1R (insulin-like growth factor 1 receptor), respectively, via a c-Jun N-terminal kinase (JNK)-dependent signaling cascade [200].