APLNR and neoplasm: Notably, the expression of mRNAs for apelin (Apln), the apelin receptor (Aplnr), the N-myc proto-oncogene, early growth protein (Egr1), and the transcription factor Sox9 were reduced by >50%, whereas the mRNA for growth arrest and DNA-damage-inducible, beta (Gadd45b) is increased >2-fold, in ventricular tissue from tumor-bearing mice compared to control mice.