IL6 and capillary leak syndrome: Moreover, adoptively transferred CAR-T cells can proliferate and persist in the body, leading to the release of large amounts of inflammatory cytokines such as TNF-α, IL-6 and IL-1 and finally cytokine release syndrome (CRS), which can result in complications such as capillary leak syndrome (CLS), disseminated intravascular coagulation (DIC) and even immune effector cell-associated neurotoxicity syndrome (ICANS), thereby limiting the clinical application of CAR-T cell therapy [114].