RB1 and retinoblastoma: As illustrated in Fig. 2b, ELTD1 showed high levels in Weri-Rb-1 cells and Rb tumors compared to fetal retina (Fetal retina versus Weri-Rb-1 cells: **p < 0.01; Fetal retina versus Rb tumors: ***p < 0.001; N = 8), but this significant difference did not extend to the aggressive Y79 cells.