PCBP2 and amyotrophic lateral sclerosis: Other genes associated with ALS/FTD development include multiple heterogeneous nuclear ribonucleoproteins (hnRNPs), such as hnRNP E2, hnRNP A1, R, Q, D, L, and I. All these proteins, predominantly associated with mRNA transcription and processing, are found in intracellular inclusions that are observed in majority of ALS and FTLD cases.