EXO1 and small cell lung carcinoma: In summary, our GWAS in LCLs, together with translational studies with DNA samples from lung cancer patients, followed by functional studies in lung cancer cell lines showed that 6 genes, PIP4K2A, CCT5, CMBL, EXO1, KMO and OPN3, genes that are close to 3 SNPs associated with SCLC overall survival (rs1778335, rs2662411 and rs7519667), significantly altered paclitaxel cytotoxicity in the SCLC cell line, H196.