Among 9 differentially methylated genomic regions associated with tree nut allergy (Supplemental Figure 4), only 1 (CXCL12) overlaps with the 12 PA-associated differential methylated genomic regions, and 6 of the 9 genes (IL10, IKZF2, CCL5, IL21, CCR9, and IL-33) have been reported to be associated with food allergy in previous studies (58–63). Here, IL21 is linked to food allergy.