I. To quantify cyclin D1, p27, phosphorylated mitogen-activated protein kinase 1 (pERK)-1/2, phosphorylated v-akt murine thymoma viral oncogene homolog 1 (pAKT), phosphatase and tensin homolog gene (PTEN), phosphorylated mammalian target of rapamycin (pMTOR), phosphorylated ribosomal protein S6 kinase (pS6K), and ribosomal protein S6 (pS6) of resected metastatic brain lesions via quantitative immunohistochemistry (IHC) and compare to the IHC profile of the primary tumor.