Bold line in forestplot

Question

How to turn a specific line bold in a forest plot using the foresplot package in R without having to use the option is.summary to select which lines become bold.

The txt_gp is set as:

txt_gp = fpTxtGp(label = gpar(fontfamily = "", cex = 1.5),
                    ticks = gpar(fontfamily = "", cex = 1.5),
                    xlab  = gpar(cex = 1.5)))

I have managed to select the first column, for example, by doing:

txt_gp = fpTxtGp(label = list(gpar(fontfamily = "", fontface = "bold", cex = 1.5),
                              gpar(fontfamily = "", fontface = "plain", cex = 1.5),
                              gpar(fontfamily = "", fontface = "plain", cex = 1.5),
                              gpar(fontfamily = "", fontface = "plain", cex = 1.5),
                              gpar(fontfamily = "", fontface = "plain", cex = 1.5),
                              gpar(fontfamily = "", fontface = "plain", cex = 1.5)),
                 ticks = gpar(fontfamily = "", cex = 1.5),
                 xlab  = gpar(cex = 1.5)))

But I'm having trouble to figuring out how to apply the following structure list[[row][[column]].

"Is there a way to make individual elements bold without using the is.summary parameter from forestplot?"

Thank you.