BTK and neoplasm: Recently, ibrutinib has been suggested to have antitumor effects in solid tumors46 through the inhibition of BTK in tumor cells or cells in the tumor microenvironment, such as MDSC, monocytes, macrophages and mast cells.46,47 In addition, the suppression of ITK may drive Th1 selective pressure in T cells48 and thus may also account for the antitumor effect of ibrutinib.