Clearing a line plotted by uitable logical cell in Matlab Guide

I have created a table in Matlab GUIDE which has logical cells(checkboxes) in the first column. A name of a signal is stored in the second column. The code below is used to plot and delete the selected signals.

% --- Executes when entered data in editable cell(s) in uitable4.
function uitable4_CellEditCallback(hObject, eventdata, handles)
data = get(handles.uitable4, 'Data');
x = handles.x;
signalPlot = handles.signalPlot;

currentRow = eventdata.Indices(1);
if eventdata.PreviousData == 0
    signalCell = data(currentRow, 2);
    signalName = signalCell{1};
    signal = evalin('base', signalName);
    axes(handles.axes2);
    hold on;
    signalPlot(currentRow) = plot(x, signal);
    hold off;
    handles.plotThis = signalPlot;
    guidata(hObject, handles);
end
if eventdata.PreviousData == 1;
   signalPlot = handles.plotThis;
   delete(signalPlot(currentRow)); 
end

This is the problematic case: When I choose 3 cellboxes, e.g. first, second and third rows. And attempt to delete the first one. I get an error:

Error using delete
Cannot access method 'delete' in class
'matlab.ui.Root'.

What can I do to achieve what I want? Thank you very much from now on.