“…Specific cellular lysis of tumour cell is mainly performed by the classic T-cell immunity mechanism (Cerottini & Brunner, 1974) or the interaction of antibody with normal lymphoid cells, the latter being referred to as antibody-dependent cellular cytotoxicity (ADCC). The precise mechanism of ADCC is not understood, though it is known that the specificity of this imimunological reaction is determined by antibody bound to membrane-associated (Lamon et al, 1976;Shore et al, 1976a) and also against Durantez & Zighelboim, 1976), histocompatibility (Yust et al, 1974; A@~~~s s , Jeannet & Vassalli, 1976) or auto-antigens (Feldmann et al, 1976). It would appear that any cell in which a virus is replicating has alterecl membrane properties which make that cell susceptible to destruction by this mechanism (Shore et al, 1976b no activity in the direct, complementdependent assay.…”