G6PD and hereditary disease: Glucose-6-phosphate dehydrogenase (G6PD), discovered in the first half of last century by Otto Warburg as “Zwischenferment” (hence the common abbreviation Zwf; [39]), has certainly attracted the most interest of all the PPP enzymes, not least because its malfunction is related to an abundant human hereditary disease with an estimated 400 million cases worldwide, which most frequently results in hemolytic anemia (see [45,46], and references therein).