SKP2 and melanoma: As shown in Figure 3A and Table 1, high expression of cytoplasmic Skp2 was detected in 33% of melanomas at AJCC stage I compared to only 55–58% of melanomas at AJCC II, III and IV (P<0.001, χ2 test); however, no significant difference was found in Skp2 expression between AJCC stage II and III or IV, indicating that increased cytoplasmic Skp2 expression may be involved in the melanoma development from stage I to II.