Model of the target-recognition mechanism by HC/2G-1 T cells. First, HC/2G-1 and tumor cells form a cell-cell interaction through CD2 and CD58. Next, peptidases such as MMP14 expressed on tumor cells cleave membrane-bound TRAIL (mTRAIL) and release soluble TRAIL (sTRAIL). Then, sTRAIL binds to DR4 and is recognized by HC/2G-1 TCR.