SIK2 and ovarian cancer: Under the activation of SIK2 overexpressed in ovarian cancers, Nap‐S in the hydrogel is phosphorylated to yield hydrophilic Nap‐Phe‐Phe‐Glu‐Glu‐Leu‐Tyr‐Arg‐Thr‐Gln‐Ser(H2PO3)‐Ser‐Ser‐Asn‐Leu (Nap‐Sp), triggering the disassembly of the hydrogel and a responsive release of the inhibitor.