ADCs Toxins, Pseudolaric acid B (PAB) is a diterpene acid isolated from the bark of P. kaempferi, a traditional Chinese medicinal plant. It has reported antifungal activities, consistent with its traditional use in the treatment of dermatological fungal infections. Moreover, PAB has diverse effects that are relevant to cancer therapy, including inducing apoptosis of cancer cells (IC50 = ~1 μM), preventing angiogenesis, and inhibiting tumor growth in vivo.