SELE and neoplasm: Since E‐selectin expression is constitutive within marrow microvessels and is also characteristic of tumor vascular beds, exofucosylated CAR‐T cells can enter marrow with greater efficiency (i.e., for CAR‐T cell therapy directed against leukemias, lymphomas, and multiple myeloma) and would also have heightened infiltration of tumor beds in solid malignancies.