Since PKP1 and RYBP (i) are involved in the development of several types of cancers, (ii) can both be oncogenes and tumor suppressors, and (iii) mutually interact with the citrullinating enzyme PADI4 [33,54], we hypothesized that RYBP could also be capable of binding to ARM-PKP1. Here, PKP1 is linked to neoplasm.