While loops is not responding

I wrote the following while loop, but when the if statement is answered, nothing happens.

 while 1
            k=StartToe+1;
            if PairsMat(PrF(end),k)<=3
                OligoPaints{i,:}=strcat(ReverseComplement(Toes(PrF(end),:),1),MainCell{i,8},ReverseComplement(Toes(k,:),1));
                PrR(q)=k;
                q=q+1;
                disp(k)
                break
            else
                k=k+1;
                if k==size(PairsMat,1)
                    errordlg('No matching toes')
                    break
                end % if k==size(PairsMat,1)
            end % if PairsMat(PrF(end),k)<=3
        end % while 1

[Adam]

Have you stepped in using the debugger? Does it ever enter the code in the if statement?