Cancer cells require a lot of energy and resources to grow and divide, sapping strength from the rest of the body. All cells, including cancer cells, use a microscopic factory called a ribosome to make the components of all growing tissues and tumours. We are studying a special protein that was named Pygopus. We have evidence and reason to think that Pygopus is part of the machine that the cancer cell uses to manufacture the ribosome factory. When we look under the microscope at cancer cells that have been marked for Pygopus protein, we see Pygopus in the regions of the genes that make ribosomes, called nucleoli. When we remove Pygopus from cancer cells, the cancer stops growing. Our work will lead us to the development of special drugs that disrupt the machinery that Pygopus uses to make ribosomes. It could also help doctors who specialize in identifying features of cancer cells make decisions on treatment.