Some genes do manifest this type of selectivity (e.g., broad dependence on CTNNB1 in colorectal cancer, MYB in leukemia, IRF4 in multiple myeloma, KRAS in pancreatic cancer, and SOX10 in skin cancer, Figure 4E), but such common essentiality within a lineage is relatively unusual. The gene discussed is IRF4; the disease is plasma cell myeloma.