**5. Conclusions**

In summary, this study provides new patient-derived chondrosarcoma cell lines with clinical and genetic information from patients. These cell lines are suitable for studying CSC subpopulations and to generate in vivo models for this disease. Furthermore, a pioneering genomic analysis using a cell line (CDS17)/xenograft line (T-CDS-17) tandem model confirmed that these cell lines kept the most relevant mutations of the original tumor and described the genetic drift process that tumor cells underwent during the adaptation to in vitro and in vivo growth.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/8/4/455/s1, Supplemental Materials and Methods, Figure S1: Computerized tomography scan (CT) at day 50 after intra-bone inoculation, Figure S2: WES analysis of chondrosarcoma cell lines, Table S1: Patient and tumor characteristics, Table S2: STR analysis for the indicated patient-derived primary cell lines and the corresponding tumor tissue of origin.

**Author Contributions:** Conceptualization, R.R.; Methodology, V.R., S.T.M., O.E., A.R., L.S., J.T., L.M.-C. and S.C.; Software, D.C. and G.R.O.; Validation, V.R. and S.T.M.; Formal analysis, V.R., S.T.M., D.C., G.R.O., S.C., and A.A.; Investigation, V.R., S.T.M., O.E., A.R., L.S., J.T., and L.M.-C.; Resources, R.R., A.A., and A.B.; Data curation, D.C. and C.A.-F.; Writing—original draft preparation, R.R.; Writing—review and editing, R.R., V.R., and S.T.M.; Supervision, R.R.; Funding acquisition, R.R.

**Funding:** This work was supported by the Agencia Estatal de Investigación (AEI) [MINECO/Fondo Europeo de Desarrollo Regional (FEDER) (SAF2016-75286-R to R.R.) and ISC III/FEDER: Miguel Servet Program (CPII16/00049 to R.R.), Sara Borrell Program (CD16/00103 to S.T.M.) and Consorcio CIBERONC (CB16/12/00390)] and the Spanish Group for Research on Sarcomas (GEIS) (project: GEIS-62). O.E. is recipient of a fellowship (Severo Ochoa Program) from PCTI-Asturias.

**Acknowledgments:** We thank Mario Garcia (Pharmacology laboratory, University of Oviedo) for his help with intra-tibia inoculations. We acknowledge the Spanish Group for Research on Sarcomas (GEIS), co-responsible institution for their support to the study. Finally, we acknowledge the Principado de Asturias BioBank (PT17/0015/0023), financed jointly by Servicio de Salud del Principado de Asturias, Instituto de Salud Carlos III and Fundación Bancaria Cajastur and integrated in the Spanish National Biobanks Network, for its collaboration.

**Conflicts of Interest:** The authors declare no competing financial interests.
