First, the fact that arginine at AIP codon 16 is a highly conserved amino acid among species (Figure 2), second, from the possibility that an occult pituitary adenoma had been present in the MSS patient in which R16H was identified, one could speculate that such an occult PRL and GH-secreting adenoma may have promoted the breast enlargement, as well as the CRC. The gene discussed is PRL; the disease is colorectal carcinoma.