CSF2 and pulmonary alveolar proteinosis: According to Table 6, excluding pulmonary alveolar proteinosis (476), The top 10 keywords with the highest frequency in 2001–2021 are colony-stimulating factor (258), disease (122), gm-csf (119), lung (95), diagnosis (67), expression (64), surfactant (23), deficient mice (24), therapy (25).