Erratum to: A qRT-PCR assay for the expression of all Mal d 1 isoallergen genes

Author details Wageningen UR Plant Breeding, Plant Research International, Droevendaalsesteeg 1, Wageningen PB 6708, The Netherlands. Department of Fruit Tree and Woody Plant Sciences, University of Bologna, Viale Fanin 46, Bologna 40127, Italy. Department of Paediatrics, University of Bologna, Via Massarenti 11, Bologna 40138, Italy. Present address: Consiglio per la Ricerca e la sperimentazione in Agricoltura-Centro di Ricerca per le Colture Industriali, via di Corticella 133, Bologna 40128, Italy.