PPBP and nonpapillary renal cell carcinoma: Previous studies have shown that CTAP/CXCL7 is the invasion, metastasis, prognosis and diagnosis of some malignancies, including breast cancers 20, 21, 22, 23, malignant pancreatic diseases 24, 25, clear cell renal cell carcinoma (ccRCC) 26, colon cancer 27, and lung cancer 10, 11, 28.