Of note, the MTT-based cytotoxicity of KH3 in a panel of cell lines revealed that KH3 at optimal dose selectively inhibited the viability of cells such as cancer cells that had high levels of HuR (IC50 < 10 μM), but had no effect on normal cell line that had low HuR (IC50 = 46 μM) [19]. This evidence concerns the gene ELAVL1 and cancer.