ARPP19 and cancer: Other gene duplications of potential interest for their role in mitosis, cancer, and stress response include cAMP-regulated phosphoprotein 19 (ARPP19), which has three copies even though we only detected expression of two copies, stomatin-like 2 (STOML2), heat shock factor binding protein 1 (HSBP1) with four copies of which two appear to be expressed, spermine synthase (SMS) and suppression of tumorigenicity 13 (ST13).