Reverse transcription PCR (RT-PCR)
RT-PCR was performed using the PrimeScript RT Reagent Kit (Perfect Real Time, Takara, Clontech), following the kit’s instructions. The absence of genomic DNA (gDNA) in cDNA samples was confirmed prior to their use by a PCR targeting exons 2-3 of PALB2 , which allowed the discrimination between gDNA and cDNA. The primers used for this test are available upon request.