Matlab - Tipo de fuente para un botón de una guide

function varargout = fuente_guide(varargin)

gui_Singleton = 1;

gui_State = struct('gui_Name',       mfilename, ...

                   'gui_Singleton',  gui_Singleton, ...

                   'gui_OpeningFcn', @fuente_guide_OpeningFcn, ...

                   'gui_OutputFcn',  @fuente_guide_OutputFcn, ...

                   'gui_LayoutFcn',  [] , ...

                   'gui_Callback',   []);

if nargin && ischar(varargin{1})

    gui_State.gui_Callback = str2func(varargin{1});

end

if nargout

    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});

else

    gui_mainfcn(gui_State, varargin{:});

end

function fuente_guide_OpeningFcn(hObject, eventdata, handles, varargin)

set(handles.pushbutton1 , 'Fontsize',15)

handles.output = hObject;

guidata(hObject, handles);

function varargout = fuente_guide_OutputFcn(hObject, eventdata, handles)

varargout{1} = handles.output;

function pushbutton1_Callback(hObject, eventdata, handles)