In a late follow-up to the frog foam story from 2009, I covered the structure of an equine protein coming from the same groups. Latherin is found in the sweat and saliva of horses and has unusual surfactant properties suggesting a new mechanism.
Read all about it in Chemistry World (free access):
NB: this came out so quickly that I actually missed it when it appeared, hence the slight delay in horn-tooting.
Some not so sweaty horses salivating over buttercups in a field near our house.