To confirm that DUSP6 was overexpressed in SKOV3 and OVCAR8 ovarian cancer SP cells, we conducted a qRT-PCR analysis and the result showed that both SP cell populations expressed higher levels of DUSP6 mRNA expression (2 to 10-fold increase) compared with non-SP (NSP) cells (P<0.001) (Figure 3a). Here, DUSP6 is linked to ovarian cancer.