Enzastaurin is primarily investigated for its potential in cancer therapy, particularly due to its ability to inhibit protein kinase C beta (PKCβ) and the PI3K/AKT signaling pathway. It has been studied in clinical trials for various malignancies, including diffuse large B-cell lymphoma (DLBCL), glioblastoma, and other solid tumors. Its mechanism involves suppressing tumor cell proliferation and inducing apoptosis, while also inhibiting angiogenesis—the formation of new blood vessels that support tumor growth. Due to its oral bioavailability and favorable safety profile in early studies, enzastaurin has been explored both as a monotherapy and in combination with chemotherapy or targeted agents. Although clinical results have been mixed, it remains of interest in oncology research, especially in biomarker-selected patient populations where pathway activation may predict response.