After identification of altered patterns of glycosylated TIMP-1 variants from a more even distribution of TIMP-1glyc1/1, TIMP-1glyc0/1, and TIMP-1glyc0/0 in the plasma of healthy donors to a strong prevalence of TIMP-1glyc1/1 in PC patient plasma (Fig. 1), we next addressed the underlying molecular mechanism. The gene discussed is TIMP1; the disease is pachyonychia congenita.