In the Cleopatra trial (trastuzumab+docetaxel vs pertuzumab+trastuzumab+docetaxel), longer OS was observed in patients with high TILs levels [16], whereas in the MA.31 trial (trastuzumab+taxane vs lapatinib+taxane) poorer prognosis was observed in case of low CD8-positive TILs on tumor samples from patients treated in the lapatinib arm relative to those receiving trastuzumab [17]. The gene discussed is CD8A; the disease is neoplasm.