PPBP and squamous cell carcinoma: In the training set, the median level of CATPIII/CXCL7 was 1302.80 (931.84, 1790.14) ng/mL in the patients with squamous cell carcinoma and 1217.14 (970.40, 1940.93) ng/mL in the patients with adenocarcinoma, all significantly higher than that in controls (840.96 (585.53, 1023.92); Fig. 1A, P < 0.0001).