ALDH4A1 and cancer: Furthermore, a subset of isoforms, including aldehyde dehydrogenase 1 family member L1 (ALDHA1L1), 3 family member B1 (ALDH3B1), 3 family member B2 (ALDH3B2), 4 family member A1 (ALDH4A1), and 7 family member A1 (ALDH7A1), show variable expression, being upregulated in certain cancers and downregulated in others.47