“…It was named parathymosin because it is similar to prothymosin alpha in size and amino acid composition (11), although they present only limited sequence homology, primarily in the C-terminal region (8,13). Both peptides were initially claimed for an immunomodulatory role acting as thymic hormones, but this role has been questioned because of their ubiquitous distribution (4,10,11,20) and their lack of a hydrophobic signal sequence necessary for their secretion (5,7,9). ParaT concentration in the different tissues studied is approximately reciprocal to that of prothymosin alpha, the former reaching the highest concentration in liver, whereas the content of prothymosin alpha in this organ is very low (1,4,10).…”