CD4 and neoplasm: To assess if mice lacking CTLs (CD8-/-, n=8), or T helper cells (CD4-/-, n=8) or eosinophils (GATA1-/-, n=8) were able to affect the growth of tumors, animals with individual genetic ablations of these three subpopulations of leukocytes were inoculated with TC-1 tumour cells.