ERCC1 and lung cancer: Later, in 2010, Ko et al. reported that emodin exhibited strong cytotoxicity against lung cancer cell lines via suppression of excision repair cross-complementing gene (ERCC) 1 and Rad 51 40; similarly, He et al. reported that emodin exerted suppressive activity against the proliferation of A549 cells in a concentration-dependent manner, and the possible molecular mechanisms involved the downregulation of ERCC1 and Rad51 41.