SPHK1 and Granuloma: When we injected sponge granulomas in mice with the sCA-encapsulated vector or SphK1 plasmid every other day, as described previously [32], the SphK1 plasmid generated clearer collagen bundles, higher fibroblast density, and less dead cell accumulation in the center of the sponge on Day 14 (Figure 6A).