Last year, scientists discovered a type of contagious cancer in soft-shell clams in which free-floating cells transmitted the disease from one animal to another.Now, a team of Columbia University researchers is reporting that contagious cancers in the ocean may be more common than previously thought and can not only jump from animal to animal, but across species. According to the new study published in Nature, the leukemia-like cancer, known as disseminated neoplasia, has been found in three more species of bivalves: mussels, cockles, and golden carpet shell clams. The cancer cells were genetically distinct from their hosts, indicating they originated elsewhere. Transmissible cancer had previously been found in Tasmanian devils and dogs, but there’s no indication that humans are at risk. “I would only worry deeply if I was a mollusk,” Stephen P. Goff, a molecular biologist at Columbia University and co-author of the study, told The New York Times