SIGLEC1 and synovial sarcoma: Interestingly, several genes expressed by APCs in the tumor mRNA were significantly higher in SS patients, including mrc1, axl, cd163, fcgr2b, marco, il18, siglec1, pecam1, csf1r, and b2m. Applying our immune module model and statistical approaches to the change in features between BL and C2 revealed more substantial changes in the mRNA profile of SS tumors as compared with MF patients (Figures S7M–S7O).