Interestingly, the targeted pathways analysis of the identified genes confirmed that in fact almost all strong loading genes of PC1, namely ALB, RBX1, TGFßR2, EP300 and TFDP1, play a role in the TGFβ pathway suggesting the TGFβ pathway as a crucial player in the development of brain metastases in primary CRC. The gene discussed is RBX1; the disease is colorectal carcinoma.