Among subtypes of breast cancer, γ1-adaptin intensity was higher in HER2 than in luminal A or luminal B. The results of the survival analysis indicated that high γ1-adaptin intensity was significantly associated with worse RFS, and this association was also observed in group with ER (+), PgR (+), HER2 (–), Ki-67 (high), or luminal B. In addition, the Cox proportional hazards model showed that high γ1-adaptin intensity was an independent prognostic factor. The gene discussed is ESR1; the disease is breast cancer.