*4.8. Statistical Analysis*

All values are presented as mean ± standard error of mean (SEM). Student's *t*-test was used to compare the experimental groups. *p*-values < 0.05 were considered statistically significant.

**Author Contributions:** Conceptualization, F.B, P.B., T.B.; methodology, E.K., K.O., R.K., F.G., F.B., B.B., T.K., E.G.; software, B.B., T.K.; validation, F.B., K.O. and T.B.; formal analysis, E.K., F.B.; investigation, E.K., K.O., K.R., E.G.; resources, F.B., P.B., T.B.; data curation, F.B.; writing—original draft preparation, E.K., F.B.; writing—review and editing, F.B.; visualization, B.B., T.K.; supervision, F.B.; project administration, F.B.; funding acquisition, F.B., T.B. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by by the European Union, cofinanced by the European Social Fund: Projects "Comprehensive Development for Implementing Smart Specialization Strategies at the University of Pécs" (EFOP-3.6.1.-16-2016-00004) and "PEPSYS—Complexity of peptide-signalization and its role in systemic diseases" (GINOP 2.3.2-15-2016-00050). This work was supported by grants EFOP-3.6.1-16-2016-00004 "Stay Alive", and GINOP-2.3.2.-15-2016-00048. B.B. was supported by the János Bolyai Research Scholarship of The Hungarian Academy of Sciences (BO/00501/19/5) and the ÚNKP-19-4-P-PTE-458 New National Excellence Program of the Ministry for Innovation and Technology.

**Acknowledgments:** The micro-CT studies were performed in the Small Animal In Vivo Imaging Core Facility of the Szentagothai Research Centre, University of Pecs. The authors express their gratitude to Tibor T. Glant, now retired, formerly at Rush University Medical Center, Chicago, IL, USA for providing us with the rhG1 antigen-producing CHO cell line and also for the several year-long fruitful scientific collaboration.

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

#### **Abbreviations**



**Figure A1.** Comparison of the quantitative markers of bone microarchitecture in arthritic Nkx2-3−/<sup>−</sup> and BALB/c mice based on the micro-CT scans (representative images are shown in Figure 2). We compared the bone pore number (Po.N) (**A**,**B**), volume (Po.V) (**C**,**D**) and surface (Po.S) (**E**,**F**), and the Bone Surface/Total Volume (BS/TV) values (**G**,**H**) of the metatarsal (**A**,**C**,**E**,**G**) and tarsal (**B**,**D**,**F**,**H**) regions from arthritic Nkx2-3−/<sup>−</sup> (black bars) and BALB/c (gray bars) mice, respectively. Bars show the mean <sup>±</sup> SEM values calculated from the data of 2 Nkx2-3−/<sup>−</sup> and 2 BALB/c mice.
