There were no significant differences in TCII and TCII-R staining between cases of feline intestinal and nodal lymphoma, or between feline intestinal and splenic mast cell tumors; however, Ki-67 staining was significantly higher in feline intestinal lymphomas compared to nodal lymphomas (p < 0.0231) and in splenic mast cell tumors compared to intestinal mast cell tumors (p < 0.0089). Here, MKI67 is linked to lymphoma.