To prove that indole derivatives impair cancer cell proliferationand to confirm their antiproliferative nature, we conducted a cellcycle distribution analysis via a propidium iodide(PI) flow cytometry assay, as reported earlier.44−46 A-549 cellswere exposed to the most potent MCT1 inhibitor, 24 (5μM), and the distribution of the cells in the cell cycle phasessub-G1, G0/G1, S, and G2/M was calculated comparedto untreated A-549 cells. Here, SLC16A1 is linked to cancer.