Results from this model suggested that, compared to having ≤ 1 friends or relatives, having 2 or more friends or relatives for emotional support was associated with a significant 20% reduced hazard of all-cause mortality (Model 3) after adjustment for age at BC diagnosis, race, time from enrollment to diagnosis, income, education, marital status, insurance, HER2, tumor ER and PR status (HR 0.80; 95% CI 0.67–0.96). This evidence concerns the gene ERBB2 and breast cancer.