We postulated that IL-10 may at least partially regulate the expression of ILT4 in human breast cancer cells; the expression of ILT4 and IL-10 might promote tumor growth and progression by inhibiting the proliferation of CD45RO + TILs and inducing the apoptosis of CD45RO + TILs in the tumor environment. The gene discussed is IL10; the disease is breast carcinoma.