As i posted earlier from LAW 360 , Purcell should pursue following highlight to 
answer successfully Micron petition.
"Nevertheless, the Patent Trial and Appeal Board  doesn’t automatically institute IPRs, despite some suggesting  otherwise. The PTAB must first decide whether to institute  an IPR by reviewing the petition, and, if filed, the optional patent owner’s preliminary  response (POPR). For the PTAB to institute, the  petitioner must show a “reasonable likelihood that the petitioner would prevail  with respect to at least 1 of the claims challenged in the  petition."
 
For any  patent hit with a petition, avoiding an IPR remains the best-case scenario,  particularly since the Federal Circuit cannot review the denial.Forward-looking  claim and specification drafting, prosecution, re-examination and reissue  practice may help better the patent owner’s odds. And filing a carefully crafted patent owner’s preliminary responsecan lead to  denial or an institution on fewer grounds and/or claims than those  presented.