[R] Greek letter included in a character vector

[Judith Flores]

Hello,

   In the past I have used "expression" to include greek letters in axis labels, 
but this time I need to include the greek letter as part of a legend. Basically, 
I need to create the following vector to rename the levels of a factor:

c("Interferon-gamma", "IL-10", "IL-5"), where "gamma" obviously needs to be 
printed as the greek letter gamma. I have tried expression("IFN-"*gramma), but 
it only works when it is isolated, not as part of a vector.

Any guidance would be very appreciated.

Thank you,

Judith