In this pilot study, we sought to extend (1) the use of the Yale Interpersonal Stressor [15] and (2) the Social Signal Transduction Theory of Depression [5] in an examination of the relation between peer-related stressors, as well as interpersonal sensitivity, and proinflammatory activity (IL-6 and TNF-α cytokines). This evidence concerns the gene IL6 and major depressive disorder.