diff --git a/docs/disease.rst b/docs/disease.rst
index eecda7b6..d46afd42 100644
--- a/docs/disease.rst
+++ b/docs/disease.rst
@@ -20,7 +20,7 @@ physicians use the word phenotype to refer to a disease, but we do not use this
 
    term, :ref:`rstontologyclass`, required, An ontology class that represents the disease
    onset, :ref:`rstage` or :ref:`rstagerange` or :ref:`rstontologyclass`, optional, an element representing the age of onset of the disease
-   disease_stage, :ref:`rstontologyclass`, optional, List of terms representing the disease stage, e.g., AJCC stage group.
+   disease_stage, :ref:`rstontologyclass`, optional, List of terms representing the disease stage e.g. AJCC stage group.
    tnm_finding, :ref:`rstontologyclass`, optional, List of terms representing the tumor TNM score