IL6 and neoplasm: However, the notion that stromal cells could promote an immunostimulating milieu is further supported by our simultaneous finding of IL-6 induction whose secretion is stimulated in TC-1 cells when they are cultured with medium conditioned by RhoB-/- fibroblasts and further enhanced when tumor cells are cultured in conditioned medium by irradiated RhoB-/- fibroblasts.