FL77-24, an analog of FL118 and an apoptosis inducer, exhibits antitumor activity with IC50 values of 99.4 nM in HCT116 cells, 118 nM in HepG2 cells, less than 6.4 nM in both MCF-7 and HeLa cells, and 28.5 nM in A549 cells. It primarily induces cell cycle arrest in the S and G2 M phases [1].