Abstract: The present invention provides genetic markers on human chromosome 6 that are associated with a beneficial response to a treatment that targets Clostridium difficile (C. difficile) toxin B (TcdB), e.g. a TcdB antibody. These TcdB treatment response markers are useful, inter alia, to identify patients who are most likely to benefit from treatment with a treatment that 5 targets TcdB in methods of treating patients having a disease susceptible to treatment with a TcdB antibody, and in methods for selecting the most appropriate therapy for such patients. The invention also provides antibodies, drug products, and kits useful with the TcdB Treatment response markers of the invention.

Abstract: Single nucleotide polymorphisms (SNPs) are provided that correlate with responsiveness of psoriasis patients to treatment with a therapeutic antibody that specifically binds to the p19 subunit of IL-23. The SNPs are used as biomarkers to prospectively selecting psoriasis patients likely to benefit from treatment with antagonists of IL-23, such as an antibody that specifically binds to the p19 subunit of IL-23.