LDHB and breast carcinoma: On the other hand, some studies reported that lactate dehydrogenase B (LDHB) gene expression was found to be reduced in many commonly used breast cancer cell lines due to the hypermethylation of the promoter area leading to gene silencing [14], while other researchers reported that upregulated gene and protein expression are seen in triple-negative cells in comparison to luminal breast cancer cells [15].