HTRA1 and Arthritis: In addition to serine protease HtrA1, which we have recently reported to associate with corneal TGFBIp amyloid in an LCD type 1 variant caused by the V624M mutation in TGFBIp [4], we identified the extracellular serine protease kallikrein-14 (kallikrein-related peptidase 14) [45,46] in the corneal amyloid samples linked to the A546D mutation in TGFBI. Human kallikreins are implicated in normal physiological processes as well as various diseases, including arthritis, cancer, and neurodegenerative diseases.