CDKN1A and chronic obstructive pulmonary disease: For example, genetic variants in CAT, GSTM1, GSTT1, GSTP1, SOD3, NFE2L2, KEAP1, OGG1, XRCC1, XRCC3, XRCC4, XRCC5, CDKN1A, and p53 are reported to be associated with COPD [54–69].