CD44 and breast carcinoma: Given this evidence, we asked if rhPRG4 suppression of TGFβ-mediated invasive growth of 3D-breast cancer cell-derived organoid as well as invasiveness and migration of cells detected by transwell invasion and scratch healing assays (Figs 1A, 2A and 2C) involves disruption of a TGFβ-controlled HA-CD44 signalling axis.