While the rabbit polyclonal Ab H-210 demonstrated lack of specificity in western blots and the murine MAb (ab 57480) showed preferential binding to a shorter isoform of brachyury, the MAb 54-1 reacted with high affinity (~100-fold compared to H-210) and marked specificity with both isoforms of brachyury in human tumor cells. The gene discussed is TBX1; the disease is neoplasm.