NGFR and melanoma: In comparison to WT, both TNFR1 KO and TNFR2 KO lost the ability to acquire resistance to either of the MAPKi, while CD271 KO did not (Fig. 3B), suggesting that TNFR1 and TNFR2 were the critical components of solTNF-mediated resistance to MAPKi in melanoma cells.