Human MASH (metabolic dysfunction-associated steatohepatitis) involves complex genetic and environmental factors. Current mouse models fail to fully imitate human MASH due to limited genetic diversity and disease susceptibility in inbred mice. Wild mice, with greater genetic diversity, offer potential for more accurate modeling of complex traits like MASH. We developed 8 chromosome 1 (Chr1) substitution strains to explore more appropriate mouse models for MASH research, focusing on lipid metabolism-related gene loci. Table 1 summarizes phenotypic screening results of these strains on a chow diet.