As such, a greater but carefully measured emphasis should be placed on uncovering the exact ways in which L-serine work particularly in the pathogenesis of certain neurological and neurodegenerative diseases and the baseline levels of the different agents, both enzymes (such as PHGDH and Serine Racemase) and substrate s(both L-serine and D-serine) that are involved in the pathway at different timepoints. This evidence concerns the gene PHGDH and neurodegenerative disease.