GRP and small cell lung carcinoma: The median concentration of proGRP level of SCLC patients was 1058.00 pg/mL (Q, 268.20‐3218.25 pg/mL), which was significantly higher than that in NSCLC (median 37.46 pg/mL, 29.61‐49.87 pg/mL) and BLD (median 37.08 pg/mL, 26.74‐54.11 pg/mL) (both P < .001; Figure 1A).