The miRNA bta-miR-449a, which was identified as a common and upregulated DE in low-RFI steers of all the three breeds, was predicted to target 16, 11, and 35 DE genes in Angus, Charolais, and KC steers, respectively, of which only three target genes including (SERPINA3, TP53INP1 and LPIN1) were common to all the three breeds. The gene discussed is SERPINA3; the disease is keratoconus.