         # @returns the expected summary grade
         expectedSummaryGrade = (grade) ->
           cumulativeGrade = grade.differentiation + grade.mitoticCount +
-            grade.necrosis_score
+            grade.necrosisScore
           if cumulativeGrade < 4
             1
           else if cumulativeGrade < 6

          else
            3

        # FIXME - the test case below once passed but now fails.
        # The test is disabled by using xit rather than it.
        # Change xit to it, fix the problem and remove this comment.
        xit 'should calculate the summary grade', ->
          for df in [1..3]
            for mc in [1..3]
              for nc in [1..2]

                  grade:
                    differentiation: df
                    mitoticCount: mc
                    necrosisScore: nc
                expected = expectedSummaryGrade(tnm.grade)
                actual = TNM.summaryGrade(tnm)
                expect(actual, "The summary grade for" +
