In contrast, the muscle fibers from OSA patients differed by having three major immunostaining patterns for desmin; (1) muscle fibers with a normal staining pattern; (2) fibers lacking or only having a weak, thin rim of subsarcolemmal staining; (3) fibers with disorganized desmin or small to large intramyofibrillar aggregates of desmin (Fig. 2). Here, DES is linked to obstructive sleep apnea syndrome.