Having corroborated the ability of CARM1 to methylate most of the detected substrates, we designed an additional 96-spot peptide array (Fig. 2e and Supplementary Data 3) with two purposes in mind: (1) to examine the significance of surrounding amino acids on CARM1-directed arginine dimethylation, particularly those mutated in human cancers; and (2) to measure PRMT specificity towards respective substrates. The gene discussed is CARM1; the disease is cancer.