RBFOX3 and amyotrophic lateral sclerosis: Furthermore, double immunostaining of YAP with several cellular markers, such as GFAP (astrocyte marker), Iba1 (microglia marker) and NeuN (neuronal marker) in the motor cortex of control mice and ALS mice showed that YAP was predominantly expressed in GFAP+ astrocytes (Figure 1E), but not in Iba1+ microglia (Figure 1F) or NeuN+ neurons (Figure 1G), and YAP was primarily located in the nucleus of GFAP+ astrocytes in ALS mice (Figure 1E), indicating activation of YAP signaling in astrocytes.