We further validated our findings in another tamoxifen-sensitive (T47D) and a relatively tamoxifen-resistant (BT474) breast cancer cell line, where NVP-231 induced significant cell death in BT474 cells but not in T47D cells (Figure 2C), confirming that tamoxifen-resistant breast cancer cells are more sensitive to CERK inhibition. Here, CERK is linked to breast carcinoma.