GPR87 and lung carcinoma: Although the Lys27Met mutation indirectly upregulates the expression of target genes by inhibiting repressive H3K27me3 modifications, H3.3 overexpression in lung cancer directly upregulates the expression of GPR87 by promoting the active histone modifications H3K4me1 and H3K9ac, which are known to be important enhancer-associated chromatin modifications33.