ERBB2 and breast neoplasm: Figure 1 depicts the structures of parent drug amiloride (Fig. 1A), C(2) derivative benzamil (Fig. 1B), C(5) derivative HMA (Fig. 1C), and C(5) derivative 10,357 (Fig. 1D)26, and summarizes the cytotoxic potency of these derivatives toward cell lines representing ER/PR-positive (MCF7), HER2-positive (SKBR3) and triple-negative (MDA-MB-231) breast tumor subtypes in an MTT cell viability assay (Fig. 1E).