CDKN1B and retinoblastoma: Besides its effect on growth factors, Tig1 overexpression also promotes the downregulation of genes encoding factors that promote cell cycle progression, and the upregulation of genes encoding the tumour suppressors Cdkn1B and Retinoblastoma (Supplementary Fig. 22), consistent with the anti-proliferative effect of Tig1 (Supplementary Fig. 6).