ANPEP and neoplasm: Stable transfection of the B9 tumor clone with the Fhit gene induced MHC-I surface expression, with recovery of the surface expression of H-2 K, D, and L molecules on the B9 tumor cells, which was mediated by transcriptional coordinated upregulation of APM, β2-microglobulin, and MHC-I heavy chain genes.