Dear All: I have a question on using coxph for multiple genes: I have written code to loop through all 22283 genes in the Hgu-133A and apply coxph on survival data. However, I don't know how to work with the result for each gene: survtest<-coxph(Surv(pcc.primary.stg.3.cox[,'fup_interval'],pcc.primary.stg. 3.cox[,'endpoint'])~pcc.primary.stg.3.cox[,'geneid'],pcc.primary.stg.3.cox) each time I tried to look at what is in survtest it gives me this: ======================================================================================== coxph(formula = Surv(pcc.primary.stg.3.cox[, "fup_interval"], pcc.primary.stg.3.cox[, "endpoint"]) ~ pcc.primary.stg.3.cox[, "208181_at"], data = pcc.primary.stg.3.cox) coef exp(coef) se(coef) z p pcc.primary.stg.3.cox[, "208181_at"] -1.87 0.154 0.688 -2.72 0.0065 Likelihood ratio test=8.56 on 1 df, p=0.00343 n= 48 ========================================================================================= What I wanted to do is to use a matrix to store each "survtest" result, but it seems to me there is no data structure in R to store the result of coxph into a matrix. I got the following code to calculate a P value based on "survtest" ================================ z<-survtest$coefficients/sqrt(surv$var) p<-2*(1-pnorm(abs(z))) then, what is the P value thus calculated? ========================================== The question I have are: 1. How do I access different parts of coxph result? 2. Is there a way to store multiple coxph results into a data structure that can be efficiently accessed? 3. if I find a list of genes I am interested, are there efficient to plot all of them based on the survial data? Thanks Hao Liu, Ph. D [[alternative HTML version deleted]]