SIK2 and ovarian cancer: In this work, by rational design of a hydrogelator Nap‐Phe‐Phe‐Glu‐Glu‐Leu‐Tyr‐Arg‐Thr‐Gln‐Ser‐Ser‐Ser‐Asn‐Leu‐OH (Nap‐S) to coassemble a SIK2 inhibitor HG‐9‐91‐01 (HG), a SIK2‐responsive supramolecular hydrogel (Gel Nap‐S+HG) for local administration and SIK2‐responsive release of HG is reported to efficiently suppress ovarian cancer metastasis.