A 23-year-old man is being evaluated for the new development of a nodule in his neck. Physical examination finds a 3.5-cm thyroid nodule. The lesion is removed surgically, and histologic sections reveal groups of poorly differentiated tumors cells within a stroma with large areas of amyloid. This familial form of this type of malignancy is associated with abnormalities of which of the following protooncogenes
ras ret myc erf