Conditions and targets studied in international and European CAR-T cells clinical trials. (A) Focus on hematologic malignancies: 21 European studies focus on lymphomas all combined, 15 studies on lymphoblastic leukemia, 8 studies on multiple myeloma and 5 studies on acute myeloid. BPDCN: Blastic plasmacytoid dendritic cell neoplasm. (B) Focus on solid tumors: 3 European studies focus on colorectal cancer, 2 studies on each glioblastoma and neuroblastoma and one study focuses on prostate cancer, malignant pleural mesothelium, melanoma and head and neck cancers. (C) Focus on targets investigated in hematologic malignancies: 28 European studies focus on CD19 targeting, 4 studies on BCMA and the following are investigated in 2 studies: CD123, CD20, CD30, dual targeting of CD19 combined with CD22 and CD19 combined with CD20. Finally, one study is investigating NKG2D, SLAMF7, TRBC1 and CD44V6 alone and the dual targeting of BCMA and TACI. These targets were studied in 45 European studies of 1087 international studies of hematological malignancies. BAFF: B-cell activating factor; BCMA: B-cell maturation antigen; CD: Cluster of differenciation; CLL-1: C-type lectin-like molecule-1; FLT3: FMS-like tyrosine kinase 3; GPRC5D: G protein–coupled receptor, class C, group 5, member D; Ig: Immunoglobulin; NKG2D: Natural Killer Group 2 membrane D; SLAMF7: Signaling Lymphocytic Activation Molecule Family Member 7; TACI: Transmembrane activator and Calcium modulating ligand interactor; TRBC1: T-cell Receptor Constant β Chain-1. (D) Focus on targets investigated in solid tumors: 4 European studies are investigating NKG2D and GD2, and the following targets are investigated in 1 study: CLDN6/Claudin18.2, PSMA, FAP and T4. These targets were studied in 12 European studies of 221 international solid tumor studies. B7-H3: B7 homolog 3 protein; BT-001: not specified; CD: Cluster of Differenciation; CEA: Carcinoembryonic Antigen; EGFR: Epidermal Growth Factor Receptor; FAP: Fibroblast Activation Protein Alpha; GD2: Disialoganglioside; GPC3: Glypican-3; GUCY2C: Guanylate Cyclase 2C; HER-2: Human Epidermal Growth Factor Receptor-2; MUC-1: Mucin 1; MMP-2: Matrix Metalloproteinase-2; NKG2D: Natural Killer Group 2 membrane D; PSMA: Prostate-Specific Membrane Antigen; ROR-1: Receptor Tyrosine Kinase Like Orphan Receptor 1; T4: Thyroxin 4; TAG72: Tumor-associated glycoprotein 72.