However, it is fair to say that netrin-1 receptors such as DCC and UNC5H are probably involved in tumour growth control and can thus be seen as tumour suppressors, even though their proactivities in low netrin-1 presence largely differ from the growth inhibitory activity of other known tumour suppressors such as Rb that constitutively repress cell cycle. The gene discussed is RB1; the disease is neoplasm.