PGF and neoplasm: In xenografts of the epidermal tumour cell line PDV C57B, derived from spindle cell squamous cell carcinoma of mouse skin, Casanova et al. found an impairment of tumour vascularisation and decreases in several growth factors associated with angiogenesis, such as vascular epithelial growth factor (VEGF), placenta-derived growth factor (PlGF) and angiopoietin-2, after treatment of nude mice with WIN 55,212-2 and JWH-133.