Ribosomes are tiny molecular machines inside all living cells that build proteins, and ribosome biogenesis is the complex, multi-step process by which they are made. During brain development, neural stem cell proliferation relies on active ribosome biogenesis to meet high protein demand. This process involves the concerted action of numerous ribosomal RNA processing factors and assembly proteins. Studies have shown that precise regulation of ribosome biogenesis is essential for normal brain development and tumor prevention.