MDM2 and cancer: More importantly, disorders in ribosome biogenesis, which induce a nucleolar stress (Boulon et al., 2010) that is monitored by the Mdm2/Hdm2-p53 pathway (Chakraborty et al., 2011; Deisenroth and Zhang, 2010), were shown to be associated with increased cancer susceptibility in animal cells (Montanaro et al., 2008; Ruggero and Pandolfi, 2003).