PIK3R1 and chronic obstructive pulmonary disease: The highest risk of COPD was conferred by the combinationof these variants of PIK3R1 (rs831125) with the GG genotypeof SIRT3 (rs536715) (OR = 3.45); and with the C alleleof PTEN (rs2735343) (OR = 3.06) and their combination:genotype GA of PIK3R1 (rs831125) together with the G alleleof SIRT3 (rs536715) and the C allele of PTEN (rs2735343)(OR = 2.86).