PTEN and cancer: Gene targeting and pharmacological studies have revealed a key role of p110β in platelet biology and thrombosis (Jackson et al., 2005) whereas recent studies have also shown a role of p110β in certain cancers and especially in tumor cells lacking PTEN (Ciraolo et al., 2008; Jia et al., 2008; Torbett et al., 2008; Wee et al., 2008; Zhu et al., 2008).