Common sites of metastases from breast, colon, lung, and prostate cancers, neuroblastomas and melanomas. A few genes shown to be involved in metastasis of the primary tumor to a specific organ are listed next to some of these organs. These lists are by no means exhaustive; many genes have been implicated in the tropism of metastases, and it is not feasible to list all of them here. LN, Lymph node.