A recent report (Liu et al. 2003) has shown that myeloma cells lacking p53 are more sensitive to arsenic trioxide (ATO), which induces apoptosis and arrest of the cells in G2/M phase of the cell cycle, whereas cells with wild-type p53 are relatively resistant to ATO and are arrested in G1 phase by ATO. Here, TP53 is linked to plasma cell myeloma.