ENU-induced T to C transition at base pair 150,929,874 (v38) on chromosome 4, or base pair 9,720 in the GenBank genomic region NC_000070 encoding Tnfrsf9. The mutation corresponds to residue 160 in the mRNA sequence NM_011612 within exon 1 of 8 total exons. The mutation results in a valine to alanine substitution at position 10 (V10A) in the CD137 protein.