HAS2 and neoplasm: Lineage tracing coupled with single-cell RNA sequencing (scRNA-seq) in sophisticated animal models categorized CAF into myofibroblast (myCAF) and inflammatory and growth factor-enriched CAF (iCAF) populations that modulate tumor cell proliferation via distinct mechanisms; the former has a high level of hyaluronan synthase 2 (Has2) that can enhance pro-tumor HA; the latter secretes HGF (Affo et al., 2021).