RT-PCR for NPM-ALK transcripts: lane 1, molecular size marker; lane 2, original blood sample of patient; lane 3, human ALCL xenograft from SCID/bg mouse; lane 4, short term tissue culture of explanted tumor cells; lane 5, negative control (no template); lane 6, t(2;5)-positive control ALCL cell line (Karpas 299); lane 7, t(2;5) negative Hodgkin cell line (KM-H2).