On uncheck the Checkbox element not removing from array?

 {
       columns.columnNames && columns.columnNames.map(el => {  
         return (
            <div>
               <input type="checkbox" value={el}  onChange={this.select_MS.bind(this)} /> {el}
             </div>
                )
           })
  }

OnChange event looks like this

select_MS(event) {

    var permissions = this.state.permissions;
    if (event.target.checked) {
        permissions.push(
            event.target.value

        )
    }


    this.setState({permissions: permissions});

After checked on 3 elements its displaying in array }

After uncheck from the elements in the array it is still showing

May i know what i am doing wrong.