MAPK1 and non-small cell lung carcinoma: Although NCI-H460 and -H520 cells constitutively expressed p-ERK protein, NFV was not able to downregulate levels of this cell survival factor in these cells (Figure 3A), suggesting that growth inhibition mediated by PIs is probably independent of inhibition of STAT 3 and ERK1/2 signalling in NSCLC cells.