PMAIP1 and neoplasm: Messenger RNA levels of Bax and of the antiapoptotic Bcl-xL (Figure 3B) and Bcl-2 (data not shown) did not change dramatically among all tumours tested, whereas Mcl-1 mRNA expression showed a small yet significant increase, but at a much lower level than the BH3-only Puma, Noxa and Bim-EL (Figure 3B and Supplementary Data).