ALK and rectum adenocarcinoma: Recently, suppressor of MEK1 homolog 2 (SMEK2)-ALK fusion variant SMEK2-ALK (S11; A2) has been reported in rectal adenocarcinoma, which fused the first 11 exons of SMEK2 to exons 2–29 of ALK, independently providing further evidence the existence of ALK rearrangement in CRC [24].