To quantitatively assess the location(s) of GRA proteins in the cyst, we measured the cyst fluorescence intensity profiles for GRA proteins, DBA, and GFP using the Fiji macro (Text S1) to measure fluorescence intensity of each cyst layer (1 pixel thick) from outside the cyst wall, through the cyst wall region, and into the cyst matrix (Fig. S3). Here, RPS19 is linked to cyst.