Kimura A, Yamasaki H, Ishii H, et al. - A marked correlation has been recorded between serotonin (5-HT) and pain modulation and the human 5-HT transporter (5-HTT) gene (SLC6A4) has been identified to exhibit several polymorphisms in its promoter region (5-HTTLPR) that affect the 5-HTT expression. As the S allele of 5-HTTLPR induces low 5-HT tone, researchers herein examined if 5-HTTLPR polymorphisms play a role in postthoracotomy pain severity. They enrolled a total of 178 patients undergoing pneumonectomy, of whom 162 patients had data available. Following genotype distribution was observed: S/S, 67.3%; S/L or L/L, 32.7%. Observations revealed no correlation of polymorphisms in 5-HTTLPR with postthoracotomy pain severity.