Interestingly, multivariable analyses (MVA) showed independent prognostic value for the pluripotency marker NANOG in PDSs cultured with MCF7 cells (HR, 2.541; 95% CI, 1.108–5.827; p = 0.028) after adjustment for ERα-status, grade, age, tumor size and lymph node metastasis (Figure 4A, Supplementary Table S6). Here, NANOG is linked to metastatic malignant neoplasm in the lymph nodes.