Correspondingly, POU2AF2 has been shown to interact with POU2F3, a master transcriptional regulator of tuft cells,8 in small cell lung cancer, characterised by high POU2F3 expression (SCLC-P).9 10 These studies suggest that tuft cell function may be influenced by genetic variation at 11q23.1; however, germline genetic regulation of these genes, and their relevance to human colonic epithelium and CRC risk, remain to be determined. Here, POU2AF2 is linked to small cell lung carcinoma.