PPM1F mRNA expression was also greater in tumor tissues from passive smokers (n=30) than in those from non-smokers (n=28), although the fold increase was not as large as that for active smokers (bar 5 vs. bar 4;10.3-fold vs. 6.3-fold, difference = 4.0-fold, 95% CI = 2.4 to 5.6-fold, *p = 0.026). Here, PPM1F is linked to neoplasm.