By demonstrating increased expression of NCAM1 and FGF/FGFRs in primary PPB in comparison to normal adult lung tissue and by demonstrating high NCAM1 expression in other primary PPB tumor biopsies, we reinforce our hypothesis that interplay between NCAM1 and FGFRs can contribute to PPB development and progression. The gene discussed is NCAM1; the disease is pleuropulmonary blastoma.