CTLA4 and colitis: For example, sequencing methods targeting 16S rRNA regions have allowed identification of microbiome-associated bioindicators that correlate with protection against CTLA-4 blockade-associated colitis (Dubin et al., 2016), presence of adenomatous polyps in patients (Hale et al., 2017), to differentiate patients with Clostridium difficile infection and non-C.