In addition, the single nucleotide polymorphisms (SNPs) of SMAD5 in the TGF-β1 signaling pathway, such as the GG genotype of SMAD6: rs12913975 and TT genotype of INHBC: rs4760259, are associated with a higher risk of brain metastasis in patients with NSCLC [146]. The gene discussed is TGFB1; the disease is non-small cell lung carcinoma.