PTPRT and pachyonychia congenita: MM-PC vs. ND-PC and U266 vs. RPMI-8226 common features: among upregulated proteins, we found an overlap of 10 proteins between patient samples and cell lines (Figure 5), such as, adhesion molecules (ICAM3 and PECAM1), which can activate a number of signaling pathways promoting survival, proliferation, migration and drug resistance of MM-PC [17,18]; B2M, which is a well-known poor prognosis biomarker for MM patients; PTPRC, a protein tyrosine phosphatase receptor, which regulate a variety of cellular processes, including cell growth, differentiation, mitosis, and oncogenic transformation.