XPNPEP1 and amyloidosis: From the overexpression of the amyloid proteins SAA4 and SAMP (encoded by genes Saa4, and Apcs) in the losers compared with the controls, we can deduce the formation of a predisposition to amyloidosis under chronic social stress in depressed mice to a greater extent as compared to the winners (which had a positive fighting experience), which did not differ from the control in these proteins’ levels.