KRT18 and breast cancer: To study the role of cisplatin, C. nutans and the combination of cisplatin and C. nutans on gene regulation, we next investigated the expression of several genes associated with breast cancer stem cells (integrin alpha 6, ITGA6, CD49f), metastatic markers (Kruppel-like Factor 4, KLF4), and differentiation markers (cytokeratin-18, KRT18; Tubulin alpha 1A, TUBA1A) (Figure 6).