FLI1 was a specific target in the erythroleukemia HEL cells (Ben-David et al., 1990), and FLI1 inhibitors were developed to treat erythroleukemia in our previous study (Li et al., 2015) Herein, we showed that L1 selectivity and specificity inhibited the erythroleukemia HEL cell line rather than in breast cancer cell lines. The gene discussed is FLI1; the disease is breast cancer.