Vitamin amino acids. Most vitamins are not single molecules, but groups of related molecules called vitamers. For example, vitamin E consists of four tocopherols and four tocotrienols. The thirteen vitamins required by human metabolism are: vitamin A (retinols and carotenoids), vitamin B (thiamine), vitamin B (riboflavin), vitamin B (niacin), vitamin B (pantothenic acid), vitamin B (pyridoxine), vitamin B (biotin), vitamin B (folic acid or folate), vitamin B (cobalamins), vitamin C (ascorbic acid), vitamin D (calciferols), vitamin E (tocopherols and tocotrienols), and vitamin K (quinones). Vitamins have diverse biochemical functions. Some forms of vitamin A function as regulators of cell and tissue
EPH receptor B2 up the largest subgroup of the receptor tyrosine kinase (RTK) family. The protein encoded by this gene is a receptor for ephrin-B family members. EphB2 is part of the NMDA signaling pathway and restoring expression rescues cognitive function in an animal model of Alzheimer's disease. A recessive EphB2 gene is responsible for the crested-feather mutation in pigeons. EPH receptor B2 has been shown to interact with: EPH receptor B2 Ephrin type-B receptor 2 is a protein that in humans is encoded by the "EPHB2" gene. Ephrin receptors and their ligands, the ephrins, mediate numerous developmental processes, particularly in the nervous