KIR2DL3 and cryohydrocytosis: As in our study, Khakoo et al. reported HLA-C2 homozygotes were more common in CHC than SC (OR 1.49, p = 0.02), and KIR2DL3-C2 homozygotes slightly more so (OR 1.87, p = 0.01); and Dring et al. reported KIR2DS3-C2 carriers were more common in CHC than SC (OR 2.26, p = 0.002).