By contrast, pronounced C5aR1 expression in a higher number of tumour samples was observed in all types of thyroid carcinomas, small-cell lung cancer, hepatocellular and cholangiocellular carcinomas, pancreatic adenocarcinomas, gastrointestinal stromal tumours, renal clear cell carcinomas and ovarian and endometrial cancer. This evidence concerns the gene C5AR1 and small cell lung carcinoma.