As shown in Fig 8A–8D, the relationship between hub genes and 22 immune cells was analyzed using pearson correlation analysis, the gene PPARG was positively correlated with monocyte in CAD across the training and validation datasets (R = 0.742, p < 0.01 and R = 0.219, p < 0.05, respectively), which revealed a potential relationship of PPARG and monocyte in CAD. Here, PPARG is linked to coronary artery disorder.