INS and ovarian cancer: In addition, the connection of SIK2 and the insulin signaling pathway has been reported in a separate study in ovarian cancer cells, which showed that SIK2 can phosphorylate the p85α regulatory subunit of PI3K at Ser154 to activate the PI3K/AKT signaling activity (42), again supporting SIK2 as a positive regulator of insulin signaling.