LDHA and neoplasm: Like normal somatic stem cells, CSCs represent only a fraction of tumor cells [4, 12, 27, 51] and are identified mainly by markers such as cell surface proteins (CD44+/CD24−, CD133+, or integrins), high aldehyde dehydrogenase (ALDH) activity, the ability to form spheres in suspension cultures, or the ability to efflux dyes to produce a side population [45, 48].