ST14 and neuroblastoma: We deleted codons Thr23-Arg558 or Thr23-Arg599 of the Her2 cDNA to produce the cDNAs Δ23-558 and Δ23-599 coding for the two site-specific Her2 CTFs, and expressed these in the M17 neuroblastoma cells determined to be negative for both Her2 and matriptase expression (data not shown).