 These cancers have a relatively stable genome as they are transmitted.Clonally transmissible cancer, caused by a clone of malignant cells rather than a virus, is an extremely rare disease modality, with few transmissible cancers being known Animals that have undergone population bottlenecks may be at greater risks of contracting transmissible cancers.Because of their transmission, it was initially thought that these diseases were caused by the transfer of oncoviruses, in the manner of cervical cancer caused by human papillomavirus.