CLPX and X-linked erythropoietic protoporphyria: The erythropoietic protoporphyrias consist of three ultra‐rare genetic disorders of the erythroid heme biosynthesis, including erythropoietic protoporphyria (EPP1), X‐linked protoporphyria (XLEPP) and CLPX‐protoporphyria (EPP2), which all lead to the accumulation of protoporphyrin IX (PPIX) in erythrocytes.