GSTM1 and inflammatory bowel disease: Gender, first-degree familiarity, the type of IBD, age at onset of BioS, age at diagnosis, disease location, perianal involvement, extraintestinal manifestations, prior surgery, being naïve to anti-TNF-α, switching from the originator, and laboratory data (CRP, ESR, Hb, fecal calprotectin) were not associated with achieving remission at the end of induction.