SHMT2 and neoplasm: The mRNA expression of target genes involved in apoptosis (BCL2-associated agonist of cell death, BAD; tumor necrosis factor superfamily, member 10, TRAIL), cell cycle (cyclin B1, CCNB1; cyclin E1, CCNE; cyclin-dependent kinase inhibitor 1A, P21CIP) and mitochondria regulation (voltage-dependent anion channel 1, VDAC), tumor survival (serine hydroxymethyl transferase 2, SHMT2), and proliferation (vasoactive intestinal peptide receptor 1, VIPR) were analyzed by real-time PCR using a multiple reference gene normalization approach [16].