All Time Lords can only regenerate 13 times (with the exception of Rassilon and the Doctor). So...
EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE! EXTERMINATE!
There, you got shot by a Dalek 13 times :D