The above-described C26 cells with different HO-1 expression levels were inoculated s.c. in Balb/c mice, and the growth of the implanted tumor is shown in Figure 5A. Compared to vehicle C26 cells, more rapid and aggressive tumor growth was observed when HO-1 over-expressed C26 cells were inoculated, whereas apparent delay of tumor growth was found for HO-1 knock-down C26 cells (Figure 5A). Here, HMOX1 is linked to neoplasm.