In another large-scale population-based prospective study, a significantly lower frequency of IgE-mediated CM allergy was documented in infants precociously exposed to CM proteins (within 14 days of life) compared to delayed introduction (between 105 and 194 days of life), allowing authors to conclude that early exposure to CM proteins, in association to breastfeeding, might promote tolerance (37). Here, IGHE is linked to cutaneous mastocytosis.