Because EGFR signaling has been recognized as an important player in CRC initiation and progression,38, 39, 40 EGFR inhibitors, which are effective in CRC harboring wild‐type RAS, have been used as one of the important molecular targeted therapies for CRC.41, 42, 43 Hence, RAS mutation analysis using plasma sample is expected to be applicable for the prediction of response to EGFR inhibitors and monitoring the change in RAS status of mCRC. Here, EGFR is linked to colorectal carcinoma.