PIKFYVE and neoplasm: Importantly, consistent with our tumor studies, PIKfyve perturbation through PIKFYVE knockdown substantially slowed the growth of PDAC cells (Fig. 3D, Extended Data Fig. 4A), and PIKfyve inhibition decreased PDAC cell viability with half-maximal inhibitory concentrations (IC50) in the nanomolar ranges for most cell lines (Extended Data Fig. 4B–C).