Lectin plant and comprises two protein domains. Abrin from the jequirity pea is similar: Lectins are ubiquitous in nature and many foods contain the proteins. Because some lectins can be harmful if poorly cooked or consumed in great quantities, "lectin-free" fad diets have been proposed, most based on the writing of Steven Gundry. A typical lectin-free diet excludes a range of foods, including most grains, pulses and legumes, as well as eggs, seafood and many staple fruits and vegetables. These foods do not contain harmful levels of lectins when properly cooked, and there is no health benefit to following these diets
Keratin used as fluorescent markers to distinguish subsets of TECs in genetic studies of the thymus. Additionally, the baleen plates of filter-feeding whales are made of keratin. Keratins (also described as cytokeratins) are polymers of type I and type II intermediate filaments, which have only been found in the genomes of chordates (vertebrates, Amphioxus, urochordates). Nematodes and many other non-chordate animals seem to only have type VI intermediate filaments, lamins, which have a long rod domain (vs. a short rod domain for the keratins). The human genome encodes 54 functional keratin genes which are located in two clusters on chromosomes 12