Provided herein are methods of treating diseases associated with vascular calcification and/or cardiovascular disease, and/or bone resorption in a subject, by using the level of a biomarker, in particular, snail homolog I (Snail), phosphosmad2, phosphosmad3, urinary protein, dickkopf homolog I (Dkkl), collagen type 1 alphal (Collal), activin (i.e.free activin), runt-related transcription factor 2 (Runx2 ), alkaline phosphatase (Alp), bone-specific alkaline phosphatase (BSAP), C-terninal type 1 collagen telopeptide (CTX), osterix, Klotho, alpha-smooth muscle actin (alpha-SMA), myocardin (JVIYOCD), activin receptor type 2A (ActRIIA), axis inhibition protein 2 (Axin2), and/or smooth muscle protein 22-alpha (Sm22-alpha), as an indicator(s) of responsiveness of the subject to the treatment, efficacy of the treatment, or appropriate dosage tor the treatment with an activin type II receptor signaling inhibitor.
