PPBP and cholangiocarcinoma: The AKT signaling pathway has been shown to be involved in human tumorigenesis and development, while the overexpression of CXCL7 in cholangiocarcinoma increased the activity of the AKT signaling pathway, suggesting that the AKT signaling pathway is involved in the malignant phenotype mediated by the CXCL7/CXCR2 axis of cholangiocarcinoma cells (Guo et al., 2017; Cheng et al., 2019).