We leveraged our access to the CAS REGISTRY, consisting of data for >250 million substances, and examined substances belonging to diverse classes such as small molecules, protein/peptide sequences, nucleic acid sequences, and others, explored in the documents related to ALS, HD, and MG in the CAS Content Collection (Figure ). For all three diseases small molecules constituted the largest fraction of explored substances (Figure ). Analysis of the annual growth of the individual substance classes is illustrated in the Supporting Information Figure ) While for journal publications the growth in the number of explored substances does not exhibit any particular trend, for patents there is clear upward trend in the number of substances as seen by their relative growths. All three classes of substances (small molecules, protein/peptide sequences, and nucleic acid sequences) show an increase in patent publications indicative of commercial interest in developing these substances as therapeutics. In particular, the nucleic acid sequence and small molecule sub-class of substances exhibit a marked increase around 2018-2019 for ALS and HD, respectively. Some specific representative substances from the protein/peptide classes are displayed in Figure in the Supporting Information and include immunosuppressive agents such as cyclosporin (CAS RN: 59865-13-3), chemotherapeutic agents such as actinomycin D (CAS RN: 50-76-0) and peptide hormone amylin (CAS RN: 106602-62-4). Other protein/peptide molecules co-occurring frequently with ALS, HD and MG include antibodies such as the CD-52 directed antibody alemtuzumab (CAS RN: 216503-57-0), VEGF-A directed antibody bevacizumab (CAS RN: 216974-75-3), and α4 integrin directed antibody natalizumab (CAS RN: 189261-10-7), among others.