The results of the multivariate analysis demonstrated that MCTS1 expression (adjusted HR = 2.564, 95% CI = 1.346–4.883, p = 0.004), M stage (adjusted HR = 13.072, 95% CI = 1.016–168.232, p = 0.049), age (adjusted HR = 2.716, 95% CI = 1.289–5.722, p = 0.009), and menopausal status (adjusted HR = 3.345, 95% CI = 1.137–9.845, p = 0.028) were independent factors of OS in patients with breast cancer (Figure 8C and Supplementary Table S5). Here, MCTS1 is linked to breast cancer.