Here, linking ribosome biogenesis plasticity with tumor cell fate, we uncover that the amino acid sensor general control non‐derepressible 2 (GCN2; also known as eIF‐2‐alpha kinase 4) represses the expression of the precursor of ribosomal RNA (rRNA), 47S, under metabolic stress. The gene discussed is EIF2AK4; the disease is neoplasm.