Fig. 2
From: Differentially hypomethylated cell-free DNA and coronary collateral circulation

Screening process for DMRs potentially associated with CCC. Selection of DMR candidates in each of the three subsets sampled by replacement from the training sets. A Volcano plots examining associations between mean differences in AMF and q values. p values are calculated using Welch’s t-test on 600,000 bins for which >90% AMF values could be calculated in each subset. Negative log-transformed q values generated using FDR correction of p values plotted for the differences in AMF between good and poor CCC groups (converted to z-scores via standardization). The area above the dashed horizontal line indicates q values <0.05. The dashed vertical line indicates the absolute z-score value |z| of 2. When the mean AMF value is significantly lower in the good CCC group than in the poor CCC group, it is indicated as hypomethylation (blue). Conversely, a high mean AMF value is indicated as hypermethylation (red). B DMRs selected from each of the three subsets. A total of 1430 DMRs commonly included in the three subsets were used in additional filtering processes. C Top 500 DMRs in each subset selected from 1430 DMRs based on the significance of the q-value. A total of 256 DMRs included in top 500 of all subsets were selected as input values for the additional random forest classifier step. D PCA results of the 256 DMRs using the AMF values of all training set samples (poor CCC: \(n=\) 29; good CCC: \(n=\) 93). E PCA results of the 256 DMRs using the AMF values of the test set samples (poor CCC: \(n=\) 5; good CCC: \(n=\) 16). The PCA results of the test set were predicted using the learning test results based on the training set