def extractColumns(mappingDf, fileTypeList, removeList):
    """
    Function to extract the sample, patient and treatment columns

    Args:
        mappingDf: Data element Table
        fileTypeList: List of instruments eg.
                      ['patient_information',
                       'treatment_information_general',
                       'sample_information',
                       'treatment_information_detailed',
                       'diagnosis_information']
        removeList: If there are any elements you want to remove,
                    pass it in as a list.
    """
    info = mappingDf['instrument'].isin(fileTypeList)
    infoCols = mappingDf['genie_field_name'][info]
    infoCols = infoCols[~infoCols.isin(removeList)].tolist()
    infoColsFirst = ['patient_id']
    infoColsFirst.extend(infoCols)
    return(infoColsFirst)