Based on the median FOXD3-AS1 expression threshold (5.045 for SCLC, 3.52 for LUAD, and 4.04 for LUSC), we divided the cancer plasma samples into low and high-FOXD3-AS1 subgroups (L-lncRNA and H-lncRNA for short). This evidence concerns the gene FOXD3 and small cell lung carcinoma.