ANPEP and neoplasm: This is of particular importance, as several TAAs, HLA class I family of proteins, APM components, and costimulatory molecules have been shown to be epigenetically silenced or downregulated in malignancies of diverse origin, hampering tumor immune recognition by cognate cytotoxic T cells and contributing to poor prognosis, including in breast and prostate cancer [1, 2, 11, 36, 37].