Change font size from the datagridview

I have a combo box and label which am using to change the font size of the lable. Now what i want is to pass it to the datagridview.

from the datagridview that i have.

I have five rows and one of the cells is a combo box with items(2.4.6.8). now i want to be able to select from the combo box and it must change the font size of the cell that i made changes on

here is my code

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)

{

lblEnos.Font = new Font(lblEnos.Font.FontFamily, Convert.ToInt32(comboBox1.SelectedItem), lblEnos.Font.Style);

}