Fig. 4. Proliferation of UCB-derived MSC when co-cultured with or without allogeneic lymphocytes at a ratio of 1 : 0 and 1 : 5 in vitro (n = 5). The MSC and Con A-activated lymphocytes were co-cultured in RPMI-1640 medium with 10% FBS, L-glutamine and antibiotics in a CO₂ incubator at 37℃ for 3 days. There was no significant (p = 0.05) difference between groups. Allogeneic lymphocytes were pre-activated with 5 µg/mL of Con A for 3 days.