KIT and gastrointestinal stromal tumor: Interestingly, the V871I, M918T, and F998V mutations are far from the ATP-binding pocket but can also inhibit TKI binding.59 In addition, NSCLC patients with positive ALK carrying the EML4-ALK fusion gene can rapidly develop alectinib resistance within three months.60 The KIT V654A and D820A mutations can cause GIST resistance to imatinib.61,62 The NTRK G623R mutation can lead to MASC resistance to entrectinib, but the next-generation NTRK-TKI selitrectinib is still effective in MASC with this mutation.18,63