LEP and skin basal cell carcinoma: Previous studies reported that CAFs can not only secrete leptin to maintain the self-renewal and invasion of BCCs but also exude interleukin-6 (IL-6) and interleukin-8 (IL-8) to promote BCC proliferation by activating the nuclear factor kappa-B (NF-κB)/p65 signaling pathway [34–36] .