NEK2 and deep vein thrombosis: Finally, the expression levels of key circRNAs (CBT15_circR_28491, CBT15_circR_6215, CBT15_circR_10888, and CBT15_circR_40191) and important hub genes (Kif18a, Cdca8, Nek2, and Ncapg) were validated in the sham and DVT groups using RT-qPCR.