Notably, 36% (n = 11) of p18−/−;Brca1MGKO and 50% (n = 6) of p16−/−;Brca1MGKO tumors, but no p18−/− tumors, metastasized to the lung (Table 1), consolidating the role of loss-of-function of Brca1 in promoting tumor metastasis. The gene discussed is BRCA1; the disease is neoplasm.