FCER2 and neoplasm: Immunohistochemical studies showed that tumor cells were positive for CD21 (Fig. 2C), CD23 (Fig. 2E), and CD35 (Fig. 2F), while negative for CD1a (Fig. 2G), C-kit, DOG1, SMA, AE1/3 (Fig. 2H), S100, SOX10, CD34, ALK, and EBER (Fig. 2D).