How to uncheck any checkbox ListItem After FindByText in C#?

i have Three Checkbox List on my page and i am adding any checked checkbox List Item to to a list box Control

and when i am removing any item from list box then i also want to Uncheck That Listitem on My checkBox List

so far i am finding which Checkbox List Contains that checkbox this and it working

but i don't Have Idea how i can Uncheck That Item wich Contains That text

if (listboxControl.SelectedIndex > 0)
   {
    string na = listboxControl.SelectedItem.Text;
    listboxControl.Items.RemoveAt(listboxControl.SelectedIndex);
    var cb1 = CheckBoxList1.Items.FindByText(na);
    var cb2 = CheckBoxList2.Items.FindByText(na);
    var cb3 = CheckBoxList3.Items.FindByText(na);
      if (cb1 != null) 
       {
           //here how i can Uncheck That Item        
       }
       else if (cb2 != null)
       {
           //here how i can Uncheck That Item 
       }
      else if (cb3 != null)
       {
            //here how i can Uncheck That Item 
       }
      else
     {

     }
 }