then he changed activeus's name to allergan. finally this summer he agreed to sell allergan's general ericks business to teva for about $40 billion. so why does this make allergan a target for pfizer? the new york-based drug giant has been looking for a way to lower its corporate tax rate. with allergan in ireland, pfizer could pursue an inversion deal, moving its headquarters overseas. and though the move would be bound to draw political scrutiny, analysts at bernstein estimate it could take pfizer's tax rate down from about 25% to 18%. an overseas deal would also let pfizer tap into its cash held outside the u.s. about 2/3 of its $30 billion horde. and analysts say it would strengthen the so-called innovative products part of pfizer's business. for a potential split of the company in a couple years. not to mention blockbuster drugs in botox and alzheimer's treatment namenda. some wonder if it's an especially good time for dealmaking in the drug world with valuations depressed in the last few months. >> we've seen lots of negat