Beta-testing of PI3-kinase inhibitors: is beta better?

Although it has been known for some time that PTEN-null tumors require expression of the p110β isoform of phosphoinositide 3-kinase for growth, the corollary demonstration that small-molecule inhibitors of p110β are effective drugs for such tumors has not been shown. This has now been rectified by the demonstration that the TGX221 analogue KIN-193 is effective in mouse xenografts of HCC70 and PC3 human tumor cell lines.