DDN and amyotrophic lateral sclerosis: mRNA levels of PCLO, coding gene for Piccolo protein, and FRMPD4 were also increased in ALS (p=0.036 and p=0.029, respectively), Finally, NRN1, which codes for neuritin 1, but not DDN, which codes for dendrin protein, was up-regulated in the frontal cortex in ALS (p=0.04 and p=0.92, respectively) (Figure 4).