Just reading up on IPR's:
smithhopen.com
..... like this part
Retaining an IPR counsel in anticipation of an IPR petition will ensure that the IPR counsel has sufficient time to thoroughly analyze the patent, its prosecution history, and the closest known prior art. This strategy will maximize the chances for the dismissal of the IPR petition, which would yield substantial savings in time and money and would provide immense leverage in settlement negotiations. Although IPRs generally favor the petitioners, a well-prepared patent owner represented by strong IPR counsel can turn the odds in its favor.