In this context, it is noteworthy that BRD4 is expressed in CD19+ B cells infiltrating the affected IBD mucosa (Franze et al., 2024a), and studies in murine splenic and peritoneal B cells showed that JQ1 inhibited IL-10 secretion, inferring the involvement of BRD4 in the function of IL-10-producing regulatory B cells (Lee et al., 2017). Here, CD19 is linked to inflammatory bowel disease.