HIPK2 and chronic obstructive pulmonary disease: Similarly, when we compared possible differentially methylated probes and their associated genes between COPD vs. non-smokers, results revealed the top 10 CpG sites such as ANGPT1 (cg22837763), PLD1 (cg22920586), NFASC (cg08830492), ACTN4 (cg25383568), RGS12 (cg05275153), CAV1 (cg15558717), PRKAG2 (cg06746365), JARID2 (cg24408769), HIPK2 (cg14630106), and MECOM (cg25010400) (Fig. 5 and Table 3).