SOX2 and non-small cell lung carcinoma: Compared with those grown in monolayer culture conditions (M), the three NSCLC spheres (S) also showed increased expression of CSC marker proteins (Sox2 and Oct4), HSP70, and client proteins of the Hsp system (HIF-1α, Akt, and Src) without detectable difference in the HSP90 expression (Figure 1B).