To determine whether SOS1 or SOS2 were required for 2D anchorage-dependent proliferation or 3D spheroid growth in EGFR-mutated NSCLC cells, SOS1 (Figure 1—figure supplement 1 and Munoz et al., 2016) or SOS2 (31) were deleted in pooled populations of HCC827 and H1975 cells to avoid clonal effects, and both proliferation and spheroid growth were assessed versus NT controls (Figure 1B and C). Here, SOS2 is linked to non-small cell lung carcinoma.