The ROH island identified on chromosome 23 in Katahdin sheep harbors genes compiled in KEGG immune pathways, including the LAMA1 gene in the ECM-receptor interaction, toxoplasmosis, and viral myocarditis pathways; TUBB6 in the phagosome, Salmonella infection and pathogenic E. coli infection pathways; and PTPRM in the adherens junction and cell adhesion molecules pathways. This evidence concerns the gene TUBB6 and toxoplasmosis.