Transcriptional regulatory Network (a) RULE1 (b) RULE2. Green rectangle: expressed gene; Red rectangle: repressed gene; Green circle: active chromatin state; Red circle: repressed chromatin state; Triangle: protein. Dash Triangle: little mount of protein. The black curve indicates repression with dash line indicating the effect is not strong. The green arrow indicates activation. RULE1 and RULE2 are represented by ①~④.