However, how IL-1 mediates CTX resistance in mCRC is still unclear.<h4>Methods</h4>Under CTX treatment, the upregulation of IL-1R1 expression and a senescence program in sensitive colorectal cancer (CRC) cell lines is examined over time using qPCR, immunoblotting, and immunofluorescence.<h4>Results</h4>In sensitive CRC cells, IL-1 appeared responsible for a CTX-mediated G0 phase arrest. Here, IL1R1 is linked to colorectal carcinoma.