In the panel of cell lines from Project Achilles, glioma cell lines consistently exhibit the largest effect sizes for community members NF1, SPRED1, and SOS1. Yet, even among glioma cell lines, only those that lack a preexisting NF1 loss‐of‐function event exhibit large differences in sensitivity to gene knockout of community members (Fig 7D). This evidence concerns the gene SPRED1 and central nervous system cancer.