Intratumoral heterogeneity helps drive the selection for diverse therapy-resistant cell populations. In this study, we demonstrate the co-existence of two therapy-resistant populations with distinct properties that are reproducibly enriched under conditions that characterize tumor pathophysiology. Breast cancer cells that survived chemotherapy or hypoxia were enriched for cells expressing the major hyaluronic acid receptor CD44. However, only CD44hi cells that survived chemotherapy exhibited cancer stem cell (CSC) phenotypes based on growth potential and gene expression signatures that represent oncogenic signaling and metastatic prowess. Strikingly, we identified TGF-β2 as a key growth promoter of CD44hi cells that survived chemotherapy but a growth inhibitor of cells that survived hypoxia. Expression of the TGFβ receptor TGFβR1 and its effector molecule SMAD4 was required for enrichment of CD44hi cells exposed to the chemotherapeutic drug epirubicin, which suggests a feed-forward loop to enrich for and enhance the function of surviving CSCs. Our results reveal context-dependent effects of TGF-β2 signaling in the same tumor at the same time. The emergence of distinct resistant tumor cell populations as a consequence of prior therapeutic intervention or microenvironmental cues has significant implications for the responsiveness of recurring tumors to therapy.