In the PCOS group, the λ of Lasso was set to 0.05051258 (Figure 4A), and 9 genes with non-zero coefficients were identified; the top 10 genes in the random forest results were selected (Figure 4B); the SVM algorithm was used to identify the 21 genes with the smallest error (Figure 4C); finally, the Venn algorithm was used to intersect the three results, and six candidate markers (RYR3, TBC1D8B, CNST, FAM166B, SLC5A3, PYY2) were identified for the PCOS group (Figure 4D). The gene discussed is PYY2; the disease is polycystic ovary syndrome.