With regard to the safety profile of T-DM1, this meta-analysis showed that patients receiving T-DM1 experienced more fatigue, elevated ALT, elevated AST, and thrombocytopenia than those receiving other anti-HER2 therapies; other anti-HER2 therapies were associated with more diarrhea, vomiting, neutropenia, leukopenia, and febrile neutropenia. The gene discussed is ERBB2; the disease is Decreased total leukocyte count.