Project Abstract Testicular cancer diagnosis and treatment, especially given its threat to sexuality and reproductive health, can be distressing in the formative period of young adulthood. Cohort studies reveal the prevalence of depressive symptoms in testicular cancer exceeds the general population. In fact, the majority of young adult cancer survivors will experience impairing, distressing, and modifiable physical, behavioral, and psychosocial adverse outcomes that persist long after the completion of primary medical treatment. These include psychological distress, impairment in the navigation and pursuit of life goals, persistent side effects, elevated risk of secondary malignancies and chronic illness, and biobehavioral burden (e.g., enhanced inflammation, dysregulated stress hormones) which influence morbidity and disease-related vulnerabilities. However, few targeted, effective interventions exist to assist young survivors in re-negotiating life goals and regulating cancer-related emotions and none focus on reducing the burden of morbidity via biobehavioral mechanisms. Young or “emerging” adulthood is a period marked by goal attainment. Chronic illness experienced as “off time” in the lifespan interrupts goal pursuits and threatens valued life directions. As young adults return to goal pursuits, re-entry to post-cancer life can be a critical point in the survivorship trajectory. Behavioral intervention at this time is well positioned to confer longer-term impact. Emergent from our group’s preliminary research, we developed and pilot-tested Goal-focused Emotion-Regulation Therapy (GET) as a novel behavioral intervention to enhance self-regulation through improved goal navigation skills, improved sense of purpose, and better ability to regulate emotional responses in young adults with testicular cancer. GET is a promising candidate intervention to address the mechanisms likely complicating the resolution of cancer-related burden. Responsive the need for feasible, effective, and scalable interventions, we will randomly allocate 300 young adult (ages 18-39) testicular cancer patients to 6 sessions of GET or ISL (individual supportive listening), and evaluate primary and secondary outcomes at baseline, post-treatment, 3-month follow-up, and 6-months follow-up. We predict that GET will be associated with superior distress outcomes and comparatively greater reductions in adverse biobehavioral indicators (dysregulated diurnal stress hormones, elevated inflammation), and these advantages will be maintained at three- and six-months following intervention. The intervention will be delivered via video conferencing to enhance access. An exploratory aim focuses on potential epigenetic vulnerabilities, to understand how environmental influences (via DNA methylation) on genes implicated in stress and mood regulation are related to cancer adjustment and intervention response. This study capitalizes on the study team’s unique expertise in biobehavioral o...