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If the data is suitable for clustering, access the clustering function through the toolbar, not form a workflow. The workflow implementation assumes the data to be clustered are found on a parent spreadsheet and the list of genes is in a child spreadsheet. Because the data to be clustered is all on one spreadsheet, select Tools from Tools from the main toolbar then toolbar then Discover then Hierarchical Clustering. Consider transposing the spreadsheet if samples are on columns and genes are on rows as Hierarchical Clustering will assume samples are rows and genes are columns. If you only have one column or one row of data, cluster only on the dimension with multiple entries by deselecting either Rows or Columns from What to Cluster or consider using an intensity plot instead.