TYK2 and posterior cortical atrophy: However, we were only able to detect strong expression of both TYK2 and MST1 proteins in ETV1-positive PCa, and silencing of ETV1 in LNCaP cells (which also leads to a drastic impair of both cell invasion and anchorage-independent growth [29]) only showed a significant effect in the expression of TYK2, but not in MST1.