Two and three loci interactions between MMP-1 rs1799750 and TIMP1rs4989 (p = 0.015), as well as MMP-1 rs1799750, MMP-9 rs17576 and TIMP-1 rs4989 (p = 0.0003) variants influencing the ROP risk were also observed. This evidence concerns the gene TIMP1 and retinopathy of prematurity.