FKBP5 and chronic obstructive pulmonary disease: The differential impact of SP-A genetic variants and sex on expression of the FKBP5 gene in the present study and on lung function in previous study (73), along with human studies shows predisposition of male sex and the FKBP5 gene for severe COPD, it will be interesting to explore further i.e., study the role of SP-A-mediated change in the FKBP5 gene in COPD patients, particularly in males.