RNA extraction and RT-PCR
The WBCs were harvested in TRIzol® reagent (Thermo Fisher) and total RNA was isolated according to the manufacturer’s instructions. cDNA was prepared from 1 µg total RNA, using the SuperScript®VI reverse transcriptase with random hexamers, following the manufacturer’s protocol (Thermo Fisher). RT-PCR was done using the primer pair of BCAP31ex1F 5’-CACGTTGACTGTGGGAAACTC-3’ and BCAP31ex4R 5’-TTCCGTCACATCATCATACTTCC-3’. All RT-PCR products were gel extracted and sequenced to confirm the normal splicing, intron inclusion, and exon skipping forms.