Given that CCR7+ cells were enriched in HPL cultures while expression of other markers conventionally used to discriminate T cell populations (including CD62L, CD127, CD27 and CD28) was not different between the serum groups (Additional file 2: Figure S1c and S1d) this raises the possibility that CCR7 expression is a signature associated with potent anti-tumor activity. Here, CD27 is linked to neoplasm.