TIMP1 and pachyonychia congenita: In an orientation study with few healthy donors (n = 6) and treatment-naïve patients (n = 5), who could donate the necessary large amount of blood (35 ml) for us to purify detectable amounts of TIMP-1 protein (see Experimental procedures), we aimed to assess the potential existence and spectrum of differential macroheterogenous glycosylation of the secreted TIMP-1 present in PC patients or healthy donors.