Define the "two-hit hypothesis" for retinoblastoma. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used. ResetHelp both copies sporadic retinoblastoma only one copy hereditary retinoblastoma of one gene must be mutated in order for retinoblastoma to develop. This hypothesis was based on the finding that always affected both eyes, whereas only affected one eye.