Whilst a 24-month Phase I trial of 15 patients treated with adenoviral-mediated VEGF-C (Lymfactin®) delivery in combination with free lymph node transfer for the treatment of secondary lymphoedema of the upper limb suggested promising results (Leppäpuska et al., 2022), results are pending from a 39-participant double blinded, placebo-controlled randomised phase II trial of (Lymfactin®) to demonstrate an objective clinical improvement in lymphoedema of the upper limb (Clinical study with Lymfactin® in the treatment of patients with secondary lymphedema—trial reference NCT03658967). This evidence concerns the gene VEGFC and lymphedema.