EGFR and colorectal carcinoma: In conclusion, we demonstrated that the detection of the TA-ness classification in primary CRC or mCRC samples shows prognostic significance in patients treated with anti-EGFR therapy and provides an additional biologic explanation for left-sided versus right-sided tumors, which is currently used for the differential anti-EGFR therapy benefit in patients.4 Whether the TA-ness classification can be used as a biomarker to improve patient selection for anti-EGFR therapy benefit in mCRC warrants additional validations in the future.