Small Body Size (SMA) and Mothers Against Decapentaplegic family 1(SMAD1), also known as JV4–1/MADH1/MADR1, which maps to human chromosome 5q4 [3], was first identified in a study of genes involved in the pathogenesis of breast cancer [4], and later considered as an important regulator in tumor progression including MM [5]. The gene discussed is SMAD1; the disease is Miyoshi myopathy.