To evaluate whether levels of INHBB and INHBC were associated with CKD progression (ESKD or doubling of serum creatinine), we tested measured INHBB and INHBC protein abundance in the African American Study of Kidney Disease and Hypertension (AASK), an external cohort of CKD patients followed for a median of 8 years and 10 months. The gene discussed is INHBC; the disease is chronic kidney disease.