Three lL of sample cDNA was mixed with 10 lL of 5-fold PrimeSTAR Buffer (TaKaRa, Japan), 4 lL of dNTP Mixture (TaKaRa, Japan) containing 2.5 mM of each dNTP, 1 lL of 20 lM primer mix (primer sequences shown in Table 1 ), 0.5 lL of PrimeSTAR HS DNA Polymerase (2.5 U/mL; TaKaRa, Japan), and 31.5 lL of distilled water.