PPP1R15A and Eczematoid dermatitis: As two illustrative examples, we identified that smCpG cg03707168 in PPP1R15A exon 2 was linked to COVID-19 infection and blood traits including mean corpuscular hemoglobin concentration, mean corpuscular volume, red blood cell distribution width, and reticulocyte count (Fig. 6A), and also that a B-cell-specific smCpG cg04545963 in NFKBIA gene was linked to lung function (FEV1/FVC ratio), asthma, eczema, cardiovascular diseases, systolic blood pressure, eosinophil count, and lymphocyte count (Fig. 6B).