Co-overexpression of Dl and ci-75 induced eye tumour-like growth in 75% of fly eyes (ey>Dl>ci75; n = 100; Figure 4H), in contrast to the overexpression of Ci full length (UAS-ci) that acts as an activator in Hh receiving cells and did not provoke eye tumour (unpublished data). This evidence concerns the gene NDUFB6 and eye neoplasm.