PCNA and cancer: Similar to the results of CSC marker genes, semiquantitative RT-PCR analysis showed that ADSCs strongly upregulate the growth-related genes in cancer cells, including MKI67 (4T1, 7.44 ± 2.43; CT26, 2.93 ± 0.29) and PCNA (4T1, 3.85 ± 1.02; CT26, 7.09 ± 1.54).