Interestingly, the HDACi 2 that was poorly active on different biological models (i.e., Xenopus laevis embryo cells and non-breast-derived malignant cancer cells, as reported by [9]) was equipotent to the parental molecule 1 toward TNBC cells, thus further underlining the importance of thorough biological characterization of bioinorganic HDAC probes in different cell model systems. The gene discussed is HDAC9; the disease is cancer.