PFKFB2 and major depressive disorder: This CpG island is located in an exon of YOD1 and in an intron of PFKFB2. The distribution of the DNA methylation beta values of the four most significant CpG sites in the YOD1 locus stratified by MDD diagnosis is shown in Fig. S1 and the distribution of the DNA methylation beta values of the other three significant CpG sites (cg18921206, cg20367479, and cg10946669) is shown in Fig. S2.