Hi, I have microarray data from a range of tumours. With each of these tumours I have some associated clinical information, including test results/scores, patient characteristics (e.g. age) and other biochemical tests (FISH etc.). I would like to do a number of things: 1) Determine whether any of these have a significant effect on the overall expression of the tumour. 2) Determine which genes expression correlate the best with a particular characteristics/test result This seems to the sort of thing you could do with linear models and limma, but it was unclear to me what is the best way forward. In particular limma seems to be set up for the experimental design rather than other external factors. Can limma take into account continuous variables rather than catergories? Any advice on this would be gratefully received as I find this whole area a bit confusing. Dan -- ************************************************************** Daniel Brewer, Ph.D. Institute of Cancer Research Email: daniel.brewer at icr.ac.uk ************************************************************** The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP. This e-mail message is confidential and for use by the addre...{{dropped}}