CCNA2 and neoplasm: Ca2+ homeostasis has been shown to be implicated in the regulation of multiple cell cycle checkpoints, for example, cyclins A and E, with the calcium/calcineurin/NFAT pathway being one of the most recognised pathways.10,42 Relatively little is known about the role of Ca2+ channels in cell motility, which is a critical step in tumour metastasis.