Compiled formula is too big to execute (5,016 characters). Maximum size is 5,000 characters

I am trying to merge some field values using formula field but its hitting the limit.

Compiled formula is too big to execute (5,016 characters). Maximum size is 5,000 characters

each fields are formula field in itself, which again references some other fields

• I understand that’s the reason, but is there a way to shorten below code? I am not sure if CASE would help here.

IF(ISBLANK(Classification_ANF_formula_GILD_E__c),'',
Classification_ANF_formula_GILD_E__c & ' ; ' )
&
IF(ISBLANK(Classification_CF_formula_GILD_E__c),'',
Classification_CF_formula_GILD_E__c & ' ; ' )
&
IF(ISBLANK(Classification_HBV_formula_GILD_E__c),'',
Classification_HBV_formula_GILD_E__c & ' ; ' )
&
IF(ISBLANK(Classification_HCV_formula_GILD_E__c),'',
Classification_HCV_formula_GILD_E__c & ' ; ' )
&
IF(ISBLANK(Classification_ONC_formula_GILD_E__c),'',
Classification_ONC_formula_GILD_E__c & ' ; ' )
&
IF(ISBLANK(Classification_HIV_formula_GILD_E__c),'',
Classification_HIV_formula_GILD_E__c & ' ; ' )
& 
IF(ISBLANK(Classification_CT_formula_GILD__c),'', 
Classification_CT_formula_GILD__c )
&
IF(ISBLANK(Classification_INF_formula_GILD_E__c),'',
Classification_INF_formula_GILD_E__c & ' ; ' )