Although there are three PIP5K1 isozymes (Figure 1C), the sensitivity of these autophagy-dependent cancer cells to the PIKFYVE inhibition by WX8 correlated only with the comparative absence of PIP5K1C protein [27], whereas PIP5K1A protein was detected in 60% of the cells at equivalent levels in both WX8-sensitive and -insensitive cells and PIP5K1B was undetectable in most of the cell lines. The gene discussed is PIP5K1C; the disease is cancer.