At 4 wk, 67% of Itga5tm1Hyn/+; Nischedsn/edsn mutants had bilateral OM and 33% had unilateral OM (n = 12), whereas in Itga5+/+; Nischedsn/edsn mice at 4 wk, 13% had bilateral OM, 63% unilateral OM and 25% showed no OM phenotype (n = 8). This evidence concerns the gene ITGA5 and ocular melanoma.