CD276 and breast cancer: In hB7-H3-expressing tumors, microbubbles conjugated to the B7-H3-targeted affibody (MBABY-B7-H3) produced higher imaging signals than nontargeted microbubbles, while in normal mammary tissues and B7-H3-blocking tumors, MBABY-B7-H3 revealed a significantly reduced signal [138], validating the diagnostic value of B7-H3 in breast cancer imaging.