Modulation of NKT Cell Development by B7-CD28 Interaction: An Expanding Horizon for Costimulation Zheng, Xincheng ; Zhang, Huiming ; Yin, Lijie ; Wang, Chyung-Ru ; Liu, Yang ; Zheng, Pan Abstract Publication: PLoS ONE Pub Date: July 2008 DOI: 10.1371/journal.pone.0002703 Bibcode: 2008PLoSO...3.2703Z