Another interesting point which came out from our studies is that the MD.45-HER/ζ cells must have the ability to traffic and target tumour cells in vivo, since these were given i.p., whereas both the ALC and FM3 tumour cells were given s.c. It is also important to note that the in vivo antitumour activity was observed in the absence of exogenously added IL-2 demonstrating that the IL-2 (and most probably also IFN-γ) produced by the MD.45-HER/ζ cells upon encounter of the tumour cells (as shown in the in vitro experiments) was sufficient for supporting their in vivo activity. Here, IL2 is linked to neoplasm.