CX3CL1 and cancer: Then, investigations on the particular relationship between PTK6 expression and chemokines with their receptors in pan-cancer analysis demonstrated that PTK6 expression was significantly positively attributed to the levels of the chemokines CCL13, CCL15, CX3CL1, CXCL1, CXCL2, CXCL3, CXCL5, CXCL6, and CXCL8 in the majority of malignancies.