PIGA and paroxysmal nocturnal hemoglobinuria: The etiology of a rare hematological disorder termed paroxysmal nocturnal hemoglobinuria (PNH) is the clonal expansion of hematopoietic stem cells carrying somatic loss-of-function mutations in PIGA, which encodes an enzyme pivotal for the biosynthesis of GPI-anchors (Hill et al., 2017; Kinoshita, 2020).