IPMKP1 and chronic obstructive pulmonary disease: Of the cessation SNPs in COPD patients from the study of Siedlinski et al. [29], two near the IPMKP1 gene were nominally associated with cessation in our study: rs9506942, and rs9552733 with P = 0.005 and P = 0.004, respectively and with the same direction of effect.