In step1 (select samples for analysis), click on sample grouping name
'Histone'. This will show 2 options namely H3k4me3 and H3K27me3. We
want to analyze the 2 histones separately. Choose H3K4me3 first by
checking radio button 'include'. This step will filter samples in
the analysis. In this case it will include only one type of selected
histone. In step2, select ``cell'' as sample grouping for further
analysis. Then choose clustering on ``Genes'' and press ``Analyze''.
Figure depicts the snapshot of this
step.