CYSLTR1 and neoplasm: Figure 7D show a statistically significant reduction of 50 μM ZM198,615-treated colonies (77.9±7.5%) compared to DMSO-treatment. Montelukast treatment showed an even stronger inhibitory effect on colony formation at the lower dosage of 12.5 μM, a reduction of 81.5±12.2% compared to DMSO-treated cells (Figure 7D). We also observed a dose-dependent reduction in colony size for both CysLT1R antagonist treatments (Figure 7E). These results suggest the importance of CysLT1R in tumor initiation.