Concentrating on the role of innate immune system in RIAE in BalB/C and SCID mice, we examined the expression of CD68 as a marker of macrophages in the tumor tissues by IHC and found that CD68 positive cells went up 2.2-2.88 fold and 1.89-1.97 fold in both irradiated tumor and abscopal tumor in BalB/C and SCID(4T1) mice, respectively (Fig. 2A, B), indicating the aggregation of macrophages in tumors after RT. Here, CD68 is linked to neoplasm.