Fig. 1. IS formation between T cells and various cells. TAGLN2 is recruited and localized at the d-SMAC during IS formation. Cofilin is also recruited at the contact site, but located at the upper region of d-SMAC as well as the central region of SMAC (c-SMAC) in which TAGLN2 is almost excluded. Differential positioning of two proteins may correspond to regulate retrograde actin flow at the IS. MTOC (microtubule-organizing center) is polarized at the region just beneath the contact site. Once MTOC is reoriented, cytokines or lytic granules move along the microtubules to the MTOC and are secreted to the surface of target cells through the cofilin-rich actin hole in c-SMAC. T cells make various types of IS, depending on the counter cells (which include APCs, cancer cells and viral infected cells).