CSF2 and neoplasm: Analysis of plasma samples from BALB/c mice with and without ranitidine treatment for the presence of colony stimulating factors (CSF1-3) that are involved in myeloid differentiation showed no differences in naïve mice, but in 4T1 tumor-bearing mice there was a significant decrease in CSF3 at day 7 in the ranitidine-treated group, which disappeared after 21 days (Figure 5A).