Although other makers (e.g. CD62L, CD27 and CD127) frequently used to define memory phenotypes were not different across the serum conditions it should be noted that CCR7 expression (and its associated gene expression profile signature) was not solely responsible for the enhanced anti-tumor effects seen in HPL-exposed cultures given that knocking out this gene did not diminish the effector function of HPL-exposed cells (Additional file 2: Figure S5 - CCR7KO HPL-cultured T cells). This evidence concerns the gene IL7R and neoplasm.