code: def load_cufflinks(self, filter_ok=True):
          
          return \
              pd.concat(
                  [self._load_single_patient_cufflinks(patient, filter_ok) for patient in self],
                  copy=False
          )
docs: Load a Cufflinks gene expression data for a cohort
  
          Parameters
          ----------
          filter_ok : bool, optional
              If true, filter Cufflinks data to row with FPKM_status == "OK"
  
          Returns
          -------
          cufflinks_data : Pandas dataframe
              Pandas dataframe with Cufflinks data for all patients
              columns include patient_id, gene_id, gene_short_name, FPKM, FPKM_conf_lo, FPKM_conf_hi