Whereas others have reported no loss of expression of MMR proteins MLH1, MSH2 or MSH6 in the non-invasive bronchioloalveolar subtype of ADC,21 we were able to demonstrate reduction of MLH1 in 71.4% and MSH2 in 28.6% of this type of carcinoma. The gene discussed is MSH6; the disease is AIDS dementia complex.