WEE1 and cancer: The WEE kinase, consisting of three family members in human, including PKMYT1 (membrane‐associated tyrosine‐ and threonine‐specific cdc2‐inhibitory kinase) and two WEE1 kinases (WEE1 and WEE1B), is protein kinase that activate the G2/M checkpoint of the cell cycle in response to double‐stranded DNA breaks.7, 8 Early study has shown that WEE1 inhibitors are effective against TP53‐mutant cancer cells, which account for over 80% of triple‐negative breast cancer (TNBC) cases.9