cfa-mir-222: Cfa-mir-222 is a microRNA associated with breast cancer in canines, identified through differential expression analysis in breast cancer mammary tissue (BCMT) compared to normal mammary tissue (BCMT-N) [PMC9917093]. It is also one of the microRNAs that showed significant upregulation in malignant canine mammary tumor tissues (MCMT-T) versus normal tissues (MCMT-N), marking the first recorded instance of such an observation [PMC9917093]. Despite its relevance, research on cfa-mir-222, particularly in canine models, is limited compared to studies on its human counterpart [PMC9917093]. To corroborate findings from high-throughput sequencing, cfa-mir-222 was included in a subset of microRNAs for validation via quantitative PCR (qPCR), although it did not show significant upregulation in the comparison between two canine fibroblast cell lines CFDP1 and CFDP2 [PMC4768678].