CXCL12 and neoplasm: It is apparent from the data that non-arthritic Balb/C mice have low expression of SDF-1 (Figure 4Cii and Dii) while SKG mice without any tumor have elevated levels of SDF-1 as noted by ELISA (Figure 4A&B) and by IHC (Figure 4Ciii and Diii and Table 3).