We analyzed further the EWAS data sets of SAH patients after reporting methylated genes related to DCI at the EWAS level (Supplementary Methods) [13 (link)]. The data involved an epigenome-wide methylation profile of CpG sites in 40 patients with aneurysmal SAH using the Infinium MethylationEPIC (EPIC) BeadChip (Illumina, San Diego, CA, USA) [13 (link)]. Raw quality probes in the raw data were filtered by the minfi package (version 1.24.0). First, the samples with detection p-values of >0.05 were discarded. Then, the remaining probes were normalized using the preprocess Funnorm algorithm implemented in the minfi package. This method eliminates undesirable variation by regressing out variability with the control probes present in our methylation microarray. Finally, the differentially methylated CpG sites (DMCpGs) were identified with a q-value cutoff of 0.01. Among the identified DMCpGs, CpG sites showing a difference in beta (β) value greater than 0.2 were used for further analysis. Finally, we selected genes with DMCpGs located in their promoter regions (±2 kb of transcription start site) and used them to infer the potential functions of the DMCpGs in terms of gene regulation.