Several single-nucleotide polymorphisms (SNPs), particularly within intronic and regulatory regions of the TNFSF4 gene (e.g., rs1234314, rs844644, rs844648, 2205960, and rs12039904), have been associated with SSc in genome-wide association studies (GWAS) and replicated in candidate gene approaches within European SSc populations [126,127]. The gene discussed is TNFSF4; the disease is systemic sclerosis.