FARP1 and cancer: Cancer-associated fibroblast-specific circ-FARP1 binds to CAV1 and inhibits its ubiquitination by ZNRF1 to enhance the secretion of LIF; in addition, circ-FARP1 sponges miR-660-3p to increase the expression of LIF, thereby promoting the stemness and GEM resistance of PDAC cells [17].