HLA-C and systemic sclerosis: The inhibitory receptor KIR2DL3 was seen at higher frequency in HLA-C*16 + controls (90.2%) than HLA-C*16 + SSc, cases (79.7%; OR = 0.44, p = 0.009), though did not differ in frequency in HLA-C*16- case-control analysis (pint = 0.02; Table 4), suggesting that the protective association of this class I allele may be mediated through inhibitory KIR, interactions.