RET and non-small cell lung carcinoma: We hypothesize that NTRK fusion (and RET fusion) may not be the primary driver alterations in NTRK+ NSCLC but may act as a secondary event due to DNA mismatch repair deficiency and thus may explain the lower ORR observed with NTRK TKIs and RET TKI in NTRK+ and RET+ CRC, respectively.