Although patient numbers in the subgroups were insufficient to apply C&RT statistics, lower levels of Hb, Hct, RDW, MCV, MCH, and platelets in the type 1 ROP group in comparison to stage 1+2 ROP and control-subgroups (p<0.005) suggest the importance of oxygen transport by RBCs. Here, GSTM1 is linked to retinopathy of prematurity.