HFE and porphyria cutanea tarda: The most frequent PCT is the acquired/sporadic type, which accounts for 75–80% of cases, in which the deficiency of UROD is limited to hepatocytes; affected patients usually present with other known risk or triggering factors such as other genetic factors (i.e., HFE mutations), viral infections (i.e., HCV-hepatitis) and exposure to certain chemical substances (i.e., alcohol, smoking, estrogens) [62].