IGF1R and colorectal cancer: In addition, more mechanisms of entrectinib resistance are being identified; these include NTRK1G595R and NTRK1G667C mutations in colorectal cancer [117], NTRK3G623R mutation in mammary analog secretory carcinoma (MASC) [118], and insulin-like growth factor-1 receptor (IGF1R) activation and increased P75 expression in neuroblastoma [119].