MTOR and infection: Post-transplant risk factors include the development of acute GvHD (aGVHD, constitutes the strongest risk factor, ×4-fold increase), positive CMV serostatus, high disease risk index, high baseline LDH level, elevated Calcineurin-inhibitor (CNI) levels, mammalian target of rapamycin inhibitors (mTORi), venous thromboembolic disease and infections (bacteremia, invasive aspergillosis and BK viremia) [16,18,23,24].