Furthermore, a tapasin transcript lacking exon 3 has been identified in a human melanoma cell line and in cells infected with human cytomegalovirus.18,19 This deletes amino acids 70–156 of tapasin, eliminating the central β sheet of the N-terminal three-tiered β sheet sandwich, which is essential for tapasin to interact with ERp57. The gene discussed is TAPBP; the disease is melanoma.