KRAS and colorectal carcinoma: In the WT-KRAS CRC patients, circ_ IFNGR2 could upregulate the expression of KRAS, activating the downstream AKT signaling and promoting the cetuximab resistance of CRC cells, while in the MUT-KRAS CRC patients, circ_ IFNGR2 contributed little to the cetuximab resistance for the persistently activated downstream signaling of KRAS.