Derivatization of this compound led to the discovery of a human PIKfyve inhibitor with an apparent IC50 of 6.2 μM, which significantly potentiated the inhibitory effect of Apilimod, an ATP‐competitive PIKfyve inhibitor under clinical trials against SARS‐CoV‐2 infection and amyotrophic lateral sclerosis. The gene discussed is PIKFYVE; the disease is amyotrophic lateral sclerosis.