MMP2 and atherosclerosis: Immunostaining showed a significant increase in Collagen I (Fig. 5A and B) and MMP2 (Fig. 5C and D) in the aorta of Abcb8ECKO mutants, corroborating the scRNAseq data and indicating that Abcb8 loss induces collagen synthesis and MMP-2 levels, both known to play a role in atherosclerosis plaque development [52,53].