Another crucial sign, not reported in the ATA guidelines, is the tearless crying which can be recognized in more than 85% of the MEN 2A/B infants and which seems to be one of the most promising signs [27], though more data are likely needed to include this manifestation as indication for RET testing in infants without any other MEN 2 symptoms and with negative family history. Here, RET is linked to multiple endocrine neoplasia.