Interestingly, through the TMA-based multiplex immunofluorescence staining, we further validated that the PODNL1 protein was especially highly expressed in cancer nests and positively correlated with FAP expression in TME in 20 types of cancer, which has been known as an important marker of activated CAFs and was verified as being associated with fibrosis and ECM degradation, and strongly expressed in the tumor stroma [42]. This evidence concerns the gene FAP and cancer.