diff --git a/README.md b/README.md
index c7dbafb..a2797fd 100644
--- a/README.md
+++ b/README.md
@@ -8,3 +8,7 @@ This is the repo for the manuscript "Spatial clonal evolution and clone-specific
 * Figure 3. Genetic changes drive tumour disparities & Cellular pathway at tumour core and edge
 * Figure 4. Clonal-specific Tumor-TME interaction 
 * Figure 5 & 6. 3D tumour structure and TME interactions 
+
+## Data Access instruction
+Data file for each data type can be access using ID listed in the file "Data_access/Sample_ID_Lookup_table_v1.xlsx"
+Please see the readme in the .xlsx file and under the folder for more instructions