Get combinations by paste in R

If you want to combine a two-value vector and a multiple-value vector in R...

do.call(paste0,expand.grid(c("mean","sd"),c("PBMC","Leu","Neu","Mono","NK","4T","8T","B")))

Then you will get meanPBMC, sdPBMC, meanLeu, sdLeu, meanNeu, sdNeu, ...