Gaucher cell accumulation in the retina of gba1−/−;smpd1−/− double mutants. (A) Analysis of the numbers of 4C4-positive cells within the retina revealed comparatively significant increases of ∼50% in both gba1−/− (P=0.0026) and gba1−/−;smpd1−/− mutants (P=0.0193) compared to those in WT, despite enhancement of key glycolipid levels in the double mutants. 4C4-positive cell counts in smpd1−/− were not statistically different to those in WT. Data represented are the mean±s.d. *P<0.05; **P<0.01 (two-way ANOVA). n= 4 for all groups. (B) 4C4-positive cells in the retina of the gba1−/− and gba1−/−;smpd1−/− double mutants were localised throughout the retina and appeared larger and rounder (arrows) compared to ramified WT 4C4-positive cells (arrowheads). Scale bar: 50 μm.