ALCAM and neoplasm: Injection of 1 × 105 ALCAM knockdown GCTB28 cells showed no tumor formation at different time points (n = 0/5 each), whereas injection of 2.5 × 104 GCTB28 cells without ALCAM knockdown induced tumor formation in the second month after inoculation (n = 4/5) (Fig. 5e, f, Table S4).