COL18A1 and Hermansky-Pudlak syndrome: In the first step of characterizing HPS, NS, and PRP, we quantitatively analyzed the concentration of three pro- (VEGF-C, PDGF-BB, and bFGF) and three anti-lymphangiogenic (TSP-1, PF-4, and endostatin) growth factors in the blood-derived secretomes.