Upon careful review of data from the quality control (QC) and quality assurance (QA) program, the authors have determined that the Frog cell line reported in this manuscript was misidentified and was actually Dal‐4. The Frog cell line was established in 2005 from a hemangiosarcoma of the spleen obtained from a 10‐year‐old female Golden Retriever. The Dal‐4 cell line was established in 2000 from a hemangiosarcoma of the spleen obtained from a 7‐year‐old male Dalmatian. The authors believe that the conclusions from this paper are not affected by the breed, age, or sex of origin of the dog from which the tumors were obtained to establish the cell lines.