SIK2 and colorectal carcinoma: In previous studies, we have confirmed that SIK2 mediates the radioresistance of CRC through its kinase activity. We then investigate whether blocking SIK2's kinase activity using inhibitors sensitizes CRC cells to IR. As expected, ARN‐3236, a small molecular inhibitor of SIK2, significantly enhanced the radiosensitivity of multiple CRC cell lines (Figure 6A, Figure S7A). Moreover, ARN‐3236 remarkably increased the growth inhibition and apoptosis effects induced by IR (Figure 6B,C).