Notably, the concentration of D-serine, a chiral form of L-serine, increases in CKD patients and is now recognized as a biomarker indicating the progression of the disease.[42] Therefore, we propose that L-serine could serve as a protective factor against IgAN through the following mechanisms: First, studies by Rodriguez and colleagues have highlighted that serine metabolism regulates macrophage inflammatory responses both in vitro and in vivo.[43] They discovered that serine metabolism is essential for producing glutathione, which is necessary for LPS-induced IL-1β mRNA expression. This evidence concerns the gene IL1B and chronic kidney disease.