The function of PYCR2 (pyrroline-5-carboxylate reductase 2, ENSG00000143811) is as follows. Oxidoreductase that catalyzes the last step in proline biosynthesis, which corresponds to the reduction of pyrroline-5- carboxylate to L-proline using NAD(P)H (PubMed:23024808, PubMed:2722838, PubMed:6894153). At physiologic concentrations, has higher specific activity in the presence of NADH (PubMed:23024808, PubMed:2722838, PubMed:6894153). Involved in cellular response to oxidative stress (PubMed:25865492). In some cell types, such as erythrocytes, its primary function may be the generation of NADP(+) (PubMed:2722838, PubMed:6894153). {ECO:0000269|PubMed:23024808, ECO:0000269|PubMed:25865492, ECO:0000269|PubMed:2722838, ECO:0000269|PubMed:6894153}.