CTLA4 promoter hypomethylation is a negative prognostic biomarker at initial diagnosis but predicts response and favorable outcome to anti-PD-1 based immunotherapy in clear cell renal cell carcinoma ====================================================================================================================================================================================================== * Niklas Klümper * Damian J Ralser * Romina Zarbl * Katrin Schlack * Andres Jan Schrader * Marc Rehlinghaus * Michèle J Hoffmann * Günter Niegisch * Annemarie Uhlig * Lutz Trojan * Julie Steinestel * Konrad Steinestel * Ralph M Wirtz * Danijel Sikic * Markus Eckstein * Glen Kristiansen * Marieta Toma * Michael Hölzel * Manuel Ritter * Sebastian Strieth * Jörg Ellinger * Dimo Dietrich