Markup in label of GtkToggleButton

["Marco Rocco" <mr85mr gmail com>]

hello, how i can use markup in a label of a gtkToggleButton? I don't
have problem to use markup on a gtkLabel or on a cell of a treeview,
for example...but in this case i suppose that i have to set markup
property on label of the GtkToggleButton, how should i do?  Thanks
you!