XCL1 and cancer: XCL1 (log2(FC) = 1.33, FDR = 8.71e-05) and SRPX2 (log2(FC) = 1.45, FDR = 0.0002) have been reported to enhance cancer progression and promote cancer migration [32,51], the up-regulation of which was mainly caused by de-methylation in the stage IV cancer.