POR and hepatocellular carcinoma: P450 oxidoreductase (POR) gene expression has been studied in few cancer types, presenting significant overall suppression of POR expression in muscle-invasive bladder cancer [86] and differentially expressed gene proteins enriched in neutrophil and T cell activation in hepatocellular carcinoma [87]; those findings support the important role of POR in carcinogenesis via alteration of the immune tumor microenvironment.