Many prognostic factors have been reported in dogs with lymphoma, such as tumor stage and substage, immunophenotype, hypercalcemia, anemia, thrombocytopenia, histopathology grade, mitotic index, anatomic location, proliferating cell nuclear antigen, aneuploidy, and proliferation indices [28,29,30]. The gene discussed is PCNA; the disease is Thrombocytopenia.