H1-5 and breast carcinoma: First, we analyzed the effect of HIST1H1B expression on breast cancer cell proliferation, and found that HIST1H1B expression led to a significant increase in the proliferation of SUM159, BT549 and Hs578T cells, whereas knockdown of HIST1H1B expression caused a remarkable decrease in MDA-468 and BT20 cell proliferation (Figure 3B).