ENU treatment induced a T-to-C transition at base pair 138,094,299 (GRCm38) on chromosome 1, or base pair 76,276 in the GenBank genomic region NC_000067. The mutation corresponds to residue 1,669 in the mRNA sequence NM_001111316 within exon 15 of 33 total exons, residue 1,350 in the mRNA sequence NM_011210 within exon 12 of 30 total exons, and residue 1,278 in the mRNA sequence NM_001268286 within exon 11 of 29 total exons. The mutation results in a serine (S) to proline (P) substitution at position 544 (p.S544P) in variant 1 of the PTPRC protein, a p.S405P substitution in variant 2, and a p.S381P substitution in variant 3.