Using control samples, the sensitivity of the NPM-ALK RT-PCR assay was shown to be at least 1:10(4).     ///    "To determine if this tumor-specific genetic alteration also occurs in HD, we performed NPM-ALK RT-PCR on RNA samples extracted from 40 lymph node biopsies of HD (25 nodular sclerosis, 11 mixed cellularity, 2 lymphocyte depleted, 2 lymphocyte predominant). "