A recent study by Vedhara et al. appearing in Psychoneuroendocrinology (2015, 52, 72–82) concluded that the personality traits of conscientiousness and extraversion were associated with the decreased and increased expression of pro-inflammatory genes, respectively. A reanalysis of the data from this study indicates that these results are fragile and ambiguous, and depend on (a) the inclusion or exclusion of two study participants missing values for one of the control variables and (b) the accumulation of statistical suppression effects in the regression analyses.