anchor.diff:  
                                           break;
                                       case "label":
  -                                        if (variable_value.indexOf("CHEMBL") != -1 && group_id == "nodes") {
  +                                        if (variable_value != null && variable_value.indexOf("CHEMBL") != -1 && group_id == "nodes") {
                                               // compound/target CHEMBLs
                                               var url = document.createElement('a');
  -                                            if(getAttributeVal(target,"Uniprot") == null){
  +                                            if(target.data["Uniprot"] == null){
                                                  url.href = 'https://www.ebi.ac.uk/chembldb/compound/inspect/' + variable_value;
                                               }else{
                                                  url.href = 'https://www.ebi.ac.uk/chembldb/target/inspect/' + variable_value;
  
positive.code:                                                 col2.textContent = variable_value;
                                                  break;
                                              } else {
                                                  if (i == (key_words.length - 1)) {
                                                      var input_text = document.createElement('input');
                                                      createEditableElement(input_text, target, variable_name, variable_value);
                                                      col2.appendChild(input_text);
                                                  }
                                              }
  
negative.code:                                             col2.appendChild(url);
                                          } else {
                                              var input_text = document.createElement('input');
                                              createEditableElement(input_text, target, variable_name, variable_value,group_id);
                                              col2.appendChild(input_text);
                                          }
                                          break;
  