Increased intrinsic apoptotic pathway activation was identified as a mechanism underlying myonuclear removal (percentage of apoptotic myonuclei of 0.64 [0.60-0.84] and 0.95 [0.84-1.2], p = 0.015 and increased percentage of activated caspase-3 positive myonuclei of 2,5 [1.6-3.3] vs. 5.7 [4.3-11], p = 0.001 in control patients and ICU patients with atrophy, respectively). Here, CASP3 is linked to Atrophy.