Association analysis of TGFβ3 copy number with DF traits showed that the copy number of TGFβ3 was significant associated with DF traits in hens (P < 0.05), hens with long DF trais seems to possess more copy number of TGFβ3. Additionally, the biological functions of copy number variation have been reported to be associated with gene expression, and multi-copy of genes has been suggested to modulate its transcription [32]. This evidence concerns the gene TGFB3 and dengue disease.