The composition of transcription factor clusters is correlated between cluster types. The correlations shown are based on the enrichment of each factor in each cluster type. (A) Promoter cluster (black) and gene clusters (white) in transcribed genes (0.46, weak correlation). (B) Gene clusters associated with methylated lysine 4 on histone H3 in transcribed (black) and silent (white) genes (0.93, strong correlation). The plots are based on data derived from K562 cells.