*4.10. Statistical Analysis*

One-way or two-way analysis of variance (ANOVA) and *t*-test were performed to identify significant differences between the control and experimental groups. All experimental data were acquired from at least three independent experiments. All statistical analyses were performed with GraphPad Prism 6.05 for Windows. A probability (*p*) value of <0.05 was considered statistically significant.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/md21020132/s1, Table S1: Antibodies used for flow cytometry; Figure S1: SEC-HPLC analysis with refractive detector of native fucoidan with F1- and F2-produced fractions; Figure S2: L-fucose does not induce apoptosis in LCLs and DLBCLs; Figure S3: Native fucoidan or vLMW-F do not (or slightly) change PD-L1 total expression; Figure S4: L-fucose does not decrease PD-L1 surface expression in LCLs and DLBCLs cells.

**Author Contributions:** Conceptualization, J.S., C.M., H.G., H.A., M.T., D.T., T.M., J.F., I.A. and C.J.- V.; methodology, J.S.; validation, J.S. and C.J.-V.; formal analysis, J.S.; investigation, J.S. and C.M.; resources, H.G., I.A., J.F. and C.J.-V.; data curation, J.S.; writing—original draft preparation, C.J.-V. and J.S.; writing—review and editing, J.S., C.M., H.G., H.A., M.T., D.T., T.M., J.F., I.A. and C.J.-V.; visualization, J.S. and C.J.-V.; supervision, C.J.-V., J.F., I.A. and M.T.; project administration, J.S. and C.J.-V.; funding acquisition, C.J.-V. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by the Ligue Nationale Contre le Cancer and Ligue Régionale Contre le Cancer (Limousin – MM/CF n◦8 & 22, Charente, Charente-Maritime). Author S.J. has received research support from Hariri Foundation for Sustainable Human Development.

**Institutional Review Board Statement:** The cell biological collection issued from Tissue and Cell Bank CRBioLim of the Limoges Hospital University Center was declared to and authorized by the French Health Ministry with session n◦ "AC-2021-4790" according to French law.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

**Acknowledgments:** We thank the flow cytometry and microscopy facilities of the BISCEm US 042 INSERM/UMS 2015 CNRS technological platform of the University of Limoges for their technical assistance as well as the immunology laboratory of the Limoges University Hospital Center. All individuals included in the section acknowledgment have consented.

**Conflicts of Interest:** The authors declare no conflict of interest.
