For example, a study examining A3AR expression (using reverse transcription polymerase chain reaction [RT-PCR] and Western blot analyses) in tumor tissues, adjacent normal tissues, and in regional lymph node metastases from patients with colon or breast carcinoma demonstrated that colon and breast carcinoma tissues had higher A3AR expression and higher A3AR protein levels compared to the adjacent healthy tissues [24]. Here, ADORA3 is linked to breast carcinoma.