MRC1 and neoplasm: The same research group reported a case–control study comparing TGFBR1*6A allelic frequency among HNPCC patients subdivided by first MMR gene mutations status and second tumour MSI status, observing a markedly elevated frequency of TGFBR1*6A carriers among MMR gene mutation-negative cases with the highest frequency among cases with MSI-negative tumours (Bian et al, 2005).