VEGFA and neoplasm: It is also possible that early-stage tumours have a greater reliance on VEGF as the principal proangiogenic factor, while in advanced tumours there may be a degree of redundancy, with angiogenesis being governed by a wider range of proangiogenic factors (Relf et al, 1997; Pavlakovic et al, 2001; Kerbel, 2004).