**Figure 4.** **Characteristics of K-means.** (**A**) The selection of optimal clustering number, the dotted line indicates the chosen number; (**B**) the result of K-means clusters, the results of clustering is shown in two-dimensions, the x axial and y axial represents the characteristics of immune cell infiltration, each dot represents a sample; (**C**) the tumor proportion in SAR1 and SAR2 group; (**D**) the cluster proportion in 7 tumor types.