P4HA1 and neoplasm: This statistically significant inverse correlation between P4HA1 and T lymphocyte gene expression levels and results obtained from GO analysis showing an impairment of T cell mediated cytotoxicity (GO:0001916; Fig. 1E) prompted to consider the involvement of P4HA1 in T lymphocyte exclusion from PDAC, a typical cold tumor [71, 72].