HSP90AB1 and schwannoma: Interestingly, not only did different forms of nitrated Hsp90 play distinct cellular and metabolic roles, their spatial distribution within the three-dimensional structure of schwannoma cell clusters differed, with increased levels of Hsp90 nitrated at Y33 in the outer cellular layer of the cell clusters, and Hsp90 nitrated at Y56 homogenously distributed throughout the three-dimensional structure.