Elucidating the effects of genetic polymorphisms on genes and gene networks is an important step in disease association studies. We developed the SNP2NMD database for human SNPs (single nucleotide polymorphisms) that result in PTCs (premature termination codons) and trigger nonsense-mediated mRNA decay (NMD). The SNP2NMD Web interfaces provide extensive genetic information on and graphical views of the queried SNP, gene, and disease terms.