# The Molecular Signature of Human Testicular Peritubular Cells Revealed by Single-Cell Analysis
## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Gene Name** & **Description** & **HTPC-1** & **HTPC-2** & \
\begin{tabular}{c} **TPCs of Nie** \\ **et al.**[17] \\ \end{tabular} &
\begin{tabular}{c} **TPCs of Di** \\ **[PERSON] et al.**[3] \\ \end{tabular} \\ \hline _ACTA2_ & Smooth-Muscle Actin & \(\surd\) & \(\surd\) & \(\surd\) & \(\surd\) \\ _ALDHIA1_ & Aldehyde Dehydrogenase 1 Family Member A1 & \(\surd\) & \(\surd\) & \(\surd\) \\ _ALDHIA2_ & Aldehyde Dehydrogenase 1 Family Member A2 & (\(\surd\)) & \(\surd\) & (\(\surd\)) \\ _ALDHIA3_ & Aldehyde Dehydrogenase 1 Family Member A3 & \(\surd\) & \(\surd\) & \(\surd\) \\ _ALDHIA3_ & Aldehyde Dehydrogenase 1 Family Member A3 & \(\surd\) & \(\surd\) & \(\surd\) \\ _AR_ & Androgen Receptor & \(\surd\) & \(\surd\) & \(\surd\) \\ _AR_ & Aristakes Related Homeobox & \(\times\) & (\(\surd\)) & \(\surd\) \\ _ARX_ & Aristakes Related Homeobox & \(\times\) & (\(\surd\)) & \(\surd\) \\ _BGN_ & Biglycan & \(\surd\) & \(\surd\) & \(\surd\) \\ _CALDI_ & Caldesmon 1 & \(\surd\) & \(\surd\) & \(\surd\) \\ _CALDI_ & Monocyte Differentiation Antigen CD14 & (\(\surd\)) & \(\times\) & \(\surd\) & \(\times\) \\ _CD19_ & B-Lymphocyte Surface Antigen B4 & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ _CD34_ & Hematopoietic Pregenitor Cell Antigen CD34 & \(\times\) & \(\times\) & \(\surd\) & \(\surd\) \\ _CD79A_ & B-Cell Antigen Receptor Complex-Associated & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\  & Protein Alpha Chain & & \(\surd\) & \(\times\) & \(\times\) \\ _CNN1_ & Calponin 1 & \(\surd\) & \(\surd\) & \(\surd\) \\ _COLIA1_ & Collagen Type I Alpha 1 Chain & \(\surd\) & \(\surd\) & \(\surd\) \\ _CXCL12_ & C-X-C Motif Chemokine Ligand 12 & \(\surd\) & \(\surd\) & \(\surd\) \\ _CYP11A1_ & Cholesterol Side-Chain Cleavage Enzyme & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ _CYP19A1_ & Aromatase & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ _DCN_ & Decorin & \(\surd\) & \(\surd\) & \(\surd\) \\ _DES_ & Desmin & \(\surd\) & \(\surd\) & \(\surd\) \\ \hline \hline \end{tabular}
\end{table} 
Table 10: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{6}{c}{**Leydig Cell Differentiation**} \\ \hline Donor & \multicolumn{6}{c}{qPCR analysis} \\ \hline  & \multicolumn{2}{c}{_LHR_} & \multicolumn{2}{c}{_INSL3_} & \multicolumn{2}{c}{_STAR_} \\ \hline
1 & Ctrl. & Diff. & Ctrl. & Diff. & Ctrl. & Diff. \\ \hline
2 & n.d. & n.d. & n.d. & n.d. & + & ++ \\ \hline
3 & n.d. & n.d. & n.d. & n.d. & + & ++ \\ \hline
4 & n.d. & n.d. & n.d. & n.d. & + & ++ \\ \hline \multicolumn{6}{c}{Osteoblast Differentiation} \\ \hline Donor & \multicolumn{6}{c}{qPCR analysis} & \multicolumn{2}{c}{Alc. ph. staining} \\ \hline  & \multicolumn{2}{c}{_COMP_} & \multicolumn{2}{c}{_ALPL_} \\ \hline  & Ctrl. & Diff. & Ctrl. & Diff. & Ctrl. & Diff. \\ \hline
1 & + & ++ & + & + & n.d. & n.d. \\ \hline
2 & + & +++ & + & + & n.d. & n.d. \\ \hline \multicolumn{6}{c}{Adipocyte Differentiation} \\ \hline Donor & \multicolumn{6}{c}{qPCR analysis} & \multicolumn{2}{c}{Oil red staining} \\ \hline  & \multicolumn{2}{c}{_PLIN1_} \\ \hline  & Ctrl. & Diff. & Ctrl. & Diff. & Ctrl. & Diff. \\ \hline
1 & n.d. & n.d. & n.d. & n.d. \\ \hline
2 & + & + & n.d. & n.d. \\ \hline
3 & + & + & + & & \\ \hline
4 & + & + & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Summary of differentiation studies. Additional HTPCs (from 2 to 4 donors) were treated as described in Materials and Methods and analyzed for Leydig cell-, osteoblast- and adipocyte-markers (Ctrl. = control group; Diff. = respective differentiation medium; n.d. = transcript not detectable; +, ++, ++ = indicates low, medium and high expression levels; Alc. ph. = alkaline phosphatase).