Although the total number of NK cells was lower in tumor-free mice than in tumor-bearing mice, sorafenib decreased the number of NK cells in both tumor-bearing and tumor-free mice (Fig. 3B, C). However, the changes of CD4+ T cells and CD8+ T cells in tumor-bearing mice were not significant (Fig. S2). Therefore, we concluded that sorafenib reduced the number of NK cells but not T cells in immunocompetent mice. Here, CD4 is linked to neoplasm.