CTC assisted PR box type correlation can lead to signaling
  It is known that there exist non-local correlations that respect no-signaling criterion, but violate Bell-type inequalities more than quantum-mechanical correlations. Such super quantum correlations were introduced as the Popescu-Rohrlich (PR) box. We consider such non-local boxes with two/three inputs and two/three outputs. We show that these super quantum correlations can lead to signaling when at least one of the input bit has access to a word line along a closed time-like curve. 
Indranil Chakrabarty, Tanumoy Pramanik, Arun K Pati, Pankaj Agrawal
quant-ph