c# CheckBox is not responding in TableLayoutPanel

I created a class extending TableLayoutPanel containing 3 columns of a CheckBox and two RichTextBoxes , I can edit and write in the textboxes but I CheckBox is not responding here's the code :

public class StepPanel : TableLayoutPanel
{
    public RichTextBox result;
    public CheckBox checkBox;
    public RichTextBox step;

    public StepPanel()
    {

        this.result = new RichTextBox();
        this.label = new CheckBox();
        this.step = new RichTextBox();
        this.ColumnCount = 3;
        this.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Absolute, 50F));
        this.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));
        this.ColumnStyles.Add(new System.Windows.Forms.ColumnStyle(System.Windows.Forms.SizeType.Percent, 50F));


        this.Controls.Add(this.checkBox, 0, 0);
        this.Controls.Add(this.step, 1, 0);
        this.Controls.Add(this.result, 2, 0); }

I then add some StepPanel's to another panel in runtime the checkbox does not change it's state when I click on it , what is wrong there ?