We have previously demonstrated that the increased number of activated and proliferating T cells following treatment of Colo26-HA tumor with immune-enhancing PDT regimens leads to increased lysis of target cells loaded with peptides derived from either the surrogate antigen, HA, or gp70, an endogenous tumor antigen expressed by Colo26-HA and the parental Colo26 tumor cell lines [5, 19]. This evidence concerns the gene EMB and neoplasm.