I found the best gene for each probe sets. However, how can I combine/put all the new gene names back into the data frame? -- output of sessionInfo(): > head(selExpr,20) GSM921888 GSM921889 GSM921890 GSM921891 OR4F17///OR4F5///OR4F4 24.3536 24.6945 LOC100134822///LINC00266-1 2004.2300 1959.5600 OR4F29///OR4F21///OR4F16///OR4F3 40.3611 42.6291 LOC100287934///LOC100287497 286.6540 253.0200 > test[delim.ind,1] [1] "OR4F17" "LOC100134822" "OR4F29" -- Sent via the guest posting facility at bioconductor.org.