Single-cell RNA sequencing has revealed a new subset, the Th1/Treg subset, characterized by T-bet and Foxp3 (characteristic Treg transcription factor) positivity (9), suggesting that during atherosclerosis progression, Treg cells lose their protective properties and develop into Th1 cells with atherogenic effects, further demonstrating the Th1 cell phenotypes’ plasticity during atherosclerosis progression (16). The gene discussed is FOXP3; the disease is atherosclerosis.