IL4I1 and neoplasm: In addition, the expression levels of IL4I1 in those with a World Health Organization tumor stage of 3–4 were significantly higher than that in those with a tumor stage of 1–2, while the expression levels of CYP1A1, OGDHL, and ASMT in those with a tumor stage of 3–4 were significantly lower than those with a tumor stage of 1–2 (Figure 4C).