CCR2 and neoplasm: Four days later, when the tumor mass had become palpable, these mice started to receive weekly intravenous administration of OKT-3/IL-2-activated, but not gene-modified, CD8+ T cells (cohort i), WT1-siTCR single-transfected CD8+ T cells (cohort ii) or CCR2 and WT1-siTCR double-transfected CD8+ T cells (cohort iii), in a total of 3 infusions.