Fig. 1. T cells have two poles and an axis of polarity. (A) The axis of polarity during (i) migration, (ii) antigen presentation and T-cell cytotoxicity, and (iii) receptor capping. (B) Model whereby a competing ligand (depicted as cell-surface associated, but it could also be a soluble ligand, such as a chemokine) recruits the MTOC and dictates the axis of polarity, preventing appropriate polarisation towards the APC (the grey arrow depicts the axis that fails to generate by the APC. (C) How the axis of polarity generated during antigen presentation can regulate the mitotic axis and the asymmetric localisation of proteins during cell division. It is possible that the APC could be replaced by other triggers of T-cell polarity to dictate asymmetric cell division.