code: def tissue_specificity(self, comment=None, entry_name=None, limit=None, as_df=False):
          
          q = self.session.query(models.TissueSpecificity)
  
          q = self.get_model_queries(q, ((comment, models.TissueSpecificity.comment),))
  
          q = self.get_one_to_many_queries(q, ((entry_name, models.Entry.name),))
  
          return self._limit_and_df(q, limit, as_df)
docs: Method to query :class:`.models.TissueSpecificity` objects in database
  
          Provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of
          multicellular organisms. By default, the information is derived from experiments at the mRNA level, unless
          specified ‘at protein level
  
          :param comment: Comment(s) describing tissue specificity
          :type comment: str or tuple(str) or None
  
          :param entry_name: name(s) in :class:`.models.Entry`
          :type entry_name: str or tuple(str) or None
  
          :param limit:
              - if `isinstance(limit,int)==True` -> limit
              - if `isinstance(limit,tuple)==True` -> format:= tuple(page_number, results_per_page)
              - if limit == None -> all results
          :type limit: int or tuple(int) or None
  
          :param bool as_df: if `True` results are returned as :class:`pandas.DataFrame`
  
          :return:
              - if `as_df == False` -> list(:class:`.models.TissueSpecificity`)
              - if `as_df == True`  -> :class:`pandas.DataFrame`
          :rtype: list(:class:`.models.TissueSpecificity`) or :class:`pandas.DataFrame`