Low expression genes may be indistinguishable from noise and will decrease the sensitivity of differential expression analysis. 

• Click the Gene counts node
• Click Filtering in the task menu
• Click Filter features (Figure 1)
  
  

• Click Noise reduction filter 
• Set the filter to maximum <= 10 
• Click Finish (Figure 2)
  
  

A new Filtered counts node will be created (Figure 3).