The clinical data for BC patients revealed the following: menopause status (212/386, 55%), unilateral tumor localization (363/386, 94%), ductal type (355/386, 92%), stage II (154/386, 40%), luminal A subtype (124/386, 32%), luminal B subtype (8/386, 23%), Her-2 positive (51/386, 13%), triple-negative (123/386, 32%), ki-67 ≥ 20% (263/386, 68%), chemotherapy responders (164/386, 43%), and gastric toxicity to chemotherapy (209/386, 54%) (Table 1). This evidence concerns the gene PSME3 and breast cancer.