TF and autosomal erythropoietic protoporphyria: The primary endpoint of our study conducted in a single‐center cohort of EPP patients was to assess whether phototest‐positive and ‐negative individuals have different levels of FEP, serum iron, serum ferritin, transferrin, transferrin saturation, serum 25‐hydroxyvitamin D (25OHD), aspartate transaminase, alanine transaminase, and gamma‐glutamyl transferase.