Predicting CAR-T–related hematotoxicity. CAR-HT predicts ICAHT in LBCL, MCL, and MM. However, it does not perform well in B-ALL. Nair et al developed a refined version of CAR-HT for B-ALL, termed ALL-HT, which predicts early ICAHT and is associated with overall survival (see Figure 4C and G in the article by Nair et al that begins on page 1136). Future research should focus on later cytopenias and infections as well as validation of ALL-HT in widely used, FDA-approved CAR products. ALL-HT, ALL-HEMATOTOX score; B-ALL, B-cell acute lymphoblastic leukemia; CAR-HT, CAR-HEMATOTOX score; ICAHT, immune effector–cell associated hematotoxicity; LBCL, large B-cell lymphoma; MCL, mantle cell lymphoma; MM, multiple myeloma. Professional illustration by Patrick Lane, ScEYEnce Studios.