It promotes carcinogenesis, tumor invasion, and drug resistance in various cancer cell types.15, 16 In our laboratory, Yang et al previously performed 2D‐DIGE combined with MALDI‐TOF‐MS analysis and found that CYPA expression was upregulated in NPC tissues from the early stage.17 Since NPC is located deeply in the nasal cavity, plasma, or serum liquid biopsy becomes an ideal noninvasive method to help the diagnosis. This evidence concerns the gene PPIA and cancer.