The article explores the intricate role of H2S in the polarization and function of macrophages in cardiac pathophysiology, including atherosclerosis. Specifically, it highlights the inhibition of cystathionine γ-lyase (CSE) expression and H2S production in macrophages by homocysteine (Hcy) and the contribution of the dysregulated CSE-H2S signaling pathway to atherosclerosis pathogenesis. This evidence concerns the gene CTH and atherosclerosis.