Breast milk is much more than just a source of nutrition; it is a complex biological fluid containing various chemicals that regulate cellular and physiological functions. These molecules include microRNAs (miRNAs), which are tiny RNAs that can regulate gene activity. Their presence has been extensively examined in human milk and that of various domestic species, but no information on their profile in marine mammal milk was accessible until recently. A new study from the University of Padua, published in the journal PLOS One, analyzed for the first time the miRNAs found in the milk of the bottlenose dolphin (Tursiops truncatus), one of the most well-known dolphin species, by combining bioinformatic analysis of its genome with miRNA sequencing from milk samples. The findings revealed that, despite the considerable morphological, metabolic, physiological, and reproductive changes that accompanied cetacean evolution into aquatic life, bottlenose dolphin milk retains several of the major microRNA families previously reported in other mammals' milk. The research, which was conducted by sequencing a pooled sample of 76 milk samples collected from two females at varying stages of lactation, identified the most abundant miRNA families, miR-148 and let-7, which have already been detected in human milk and the milk of several domestic species, including donkeys, goats, sheep, and cattle. The collection was conducted as part of routine veterinary and welfare monitoring activities by the Experimental Zooprophylactic Institute of Lazio and Tuscany and the Local Health Authority (ASL). The discovery of the same miRNA families in dolphins as in terrestrial mammals is of tremendous evolutionary interest: despite the profound alterations undergone by cetaceans, the key regulatory components of milk have remained the same as in terrestrial species.