Statistically significant prognostic variables were: the biological subtype (hormone receptor, HR−/HER2−, HR+/HER2−; HR ± /HER2+), treatment with trastuzumab (yes vs. no), KPS (≥70 vs. 70), age (≥50 vs. <50) and lymphopenia at BM diagnosis (>700 vs. ≤700). The gene discussed is ERBB2; the disease is lymphopenia.