PIK3R1 and small cell lung carcinoma: To summarize, this study found three miRNA-related SNPs (MTOR: rs2536 (T>C), PIK3R1: rs3756668 (A>C) and PIK3R1: rs12755 (A>G)) in the PI3K/Akt/mTOR pathway and pathway-based RPA that were associated with survival in patients with LD SCLC treated with chemoradiotherapy.