PARP1 and cancer: Besides, PARP1 protein level is significantly up-regulated in CRC cancer tissues compared with normal tissues, according to immunohistochemistry results (Fig. 6g) and a on line database UALCAN (ualcan.path.uab.edu/index.html) [49], which indicating PARP1 is also a potential therapeutic target to inducing parthanatos in CRC (Additional file 4: Fig. S4c).