CD177 and glycogen storage disease VI: Serum levels of MMP-12 were significantly lower in the early SSc group [0.07 ng/mL (0.03-0.10) in early SSc vs. 0.15 ng/mL (0.09-0.20) in long-standing disease; p = 0.003] and CD177 [9.13 ng/mL (6.24-11.3) in early SSc vs. 12.3 ng/mL (9.34-20.0) in long-standing disease; p = 0.03].