Davidson B, et al. - In metastatic high-grade serous carcinoma (HGSC), the researchers examined the expression and clinical role of CHK1 and CHK2. Using immunohistochemistry, HGSC effusions (n = 335; 280 peritoneal, 55 pleural) were analyzed for protein expression of total CHK1 and its phosphorylated forms p-ser317 and p-ser296, as well as total CHK2 and its phosphorylated form p-thr68. The findings demonstrated that CHK1 and CHK2 and their activated forms were often expressed in HGSC effusions, with higher expression after chemotherapy exposure. Additionally, their expression was related to survival.