Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit γ (PIK3CG) was identified in multiple upregulated pathways for the metastatic brain tumors and gene expression was significantly increased in metastatic melanoma samples in comparison to primary melanoma from TCGA data (Fig. 3c). Here, PIK3CG is linked to metastatic melanoma.