CD8A and breast cancer: proved that the CBS‐H2S axis creates colorectal cancer (CC)‐friendly immune microenvironment by downregulating the CD8+ T cell/Treg ratio.[46] One potential explanation for this discrepancy might be that the CTH protein exceeds the CBS protein by ≈12‐fold in BC tissues, indicating that CTH is the dominant source of endogenous H2S in BC.