Update README.md

README.md

@@ -13,9 +13,9 @@ CALDER is a Hi-C analysis tool that allows: (1) compute chromatin domains from w
 * Calder connects chromatin 3D organization to genomic function:
 ![Alt text](./img/CALDER_features.png "CALDER features")
 
-## (A note on the performance of Calder vs PC)
+## (A note on the performance of Calder vs PC-based approach)
 
-* Except for being able to identify non-linear sub-compartments, Calder demonstrates superior robustness over PC-based approach in identifying meaningful compartments, particularly when faced with complex chromosomal structural variations (figure on the left) and loose interaction between the p and q arms (figure on the right)
+* The sign of PC1 was typically used to define A/B compartment. We found Calder demonstrates superior robustness over PC-based approach in identifying meaningful compartments, particularly when faced with complex chromosomal structural variations (figure on the left) and loose interaction between the p and q arms (figure on the right)
 
 ![Alt text](./img/Hela_chr11_and_RWPE1_chr9_pq.png "Hela_chr11_and_RWPE1_chr9_pq")