As shown in Table 2, we found that ABCG2 expression was significantly associated with tumor size (6.1 cm ± 2.7 cm vs. 3.9 cm ± 1.5 cm, p = 0.01) and the response to chemotherapy (62.4% ± 25.1% vs. 75.3% ± 18.7%, p = 0.02). This evidence concerns the gene ABCG2 and neoplasm.