Couldn't generate code for the following reason:
Variable has units micromolar which are incompatible with the units dimensionless on a connected variable.; 
  In MathML apply element.
  In MathML math element.
  In CellMLComponent element with cmeta:id P_C1 with name P_C1.
  In Model element with cmeta:id keizer_model_1996 with name keizer_levine_1996_version01.