ERBB2 and neoplasm: Furthermore, histopathological analysis of lung sections obtained from UniCAR+BT treated mice revealed human CD4+ and CD8+ lymphocyte infiltration in the vicinity of biotin and/or HER2-positive cells and this off-tumor on-target effect may have sequestered a part of the CD8+ fraction of the therapeutic cell product, causing a consequent CD4+ accumulation in the tumor.