VAPA and small cell lung carcinoma: Furthermore, we generated the construction of overexpressing circVAPA (OE-circVAPA) with its endogenous flanking sequences including complementary Alu element pairs to gain the function of the ectopic circVAPA. As depicted in Fig. 3A, OE-circVAPA dramatically increased the circVAPA expressions and unchanged the VAPA mRNA levels in SCLC cells.