SIK2 and ovarian cancer: SIK2 inactivation in SKOV-3 raised the mean chromosome number from 47.54 to 76.86, while in OVCAR-3, the number of chromosomes increased from 58.83 to 71.26, respectively (Figure 4B–G), demonstrating that inhibition of SIK2 activity promoted chromosomal instability in ovarian cancer.