How do I set gtk.RadioButton font?

[Google Mike]

Nikos Kouremenos <nk at ebox.gr> wrote in message 
> GLADE XML is better (especially for such stuff)
> just enable the USE_MARKUP and then right in the "text"
> <small>YOU_TEXT</small>
> 
> here is a label of a quick label I clicked in GLADE, and glade wrote this:
> 
> 		<widget class="GtkLabel" id="label33">
> 		  <property name="visible">True</property>
> 		  <property name="label" translatable="yes"><span 
> background="lightgreen"><big>Welcome</big></span>
> <small><span background="white">If you change the 
> settings don't forget to Save &amp; Activate in a 
> Profile!</span></small>
> </property>
> 		  <property name="use_underline">False</property>
> 		  <property name="use_markup">True</property>
> 		  <property name="justify">GTK_JUSTIFY_CENTER</property>
> 		  <property name="wrap">False</property>
> 		  <property name="selectable">False</property>
> 		  <property name="xalign">0.5</property>
> 		  <property name="yalign">0.5</property>
> 		  <property name="xpad">0</property>
> 		  <property name="ypad">0</property>
> 		</widget>

Unfortunately this has no effect on a radiobutton item.