NOS2 and Distal myopathy, Nonaka type: This cell stress response does not appear to be specific to GNEmyopathy, but could be an underlying event with relevance to other myopathies: In sIBM, NO has recently been demonstrated to play an important pathogenic role as evidenced by an upregulation of the key NO-producing enzyme iNOS in muscle cells exposed to pro-inflammatory cytokines [13].