LDHA and cancer: ALDHs refer to a group of enzymes that catalyze the oxidation of aldehydes to carboxylic acids, which can be further classified into 3 classes in mammals.327 Physiologically, ALDHs are present in most tissues of humans and have the highest concentration in livers, orchestrating drug metabolism.328 This also indicates an important role of ALDH in cancer drug resistance.329 ALDH activity has been considered a marker for not only normal stem cells but also CSCs of solid and hematopoietic malignancies.330