ALK and colorectal carcinoma: We report a case of metastatic CRC with an ALK-CEP44 fusion not previously described in this tumor type, associated ALK overexpression, a notable clinical response to the ALK inhibitor alectinib, and rapid development of multiple ALK resistance mutations.<h4>Case summary</h4>A 60-year-old male patient was diagnosed with stage IIIA right-sided CRC.