Some proteins involved in amino acid biosynthesis were differentially affected in abundance by OS in this study, such as S-adenosylmethionine synthase (methionine adenosyltransferase, SAMS), methionine synthase (MetS) and d-3-phosphoglycerate dehydrogenase (PHGDH) (Fig. 2, Supplementary Fig. S1, Table 1). Here, MTR is linked to metabolic syndrome.