STK38 and renal carcinoma: To functionally validate this, we manipulated STK38 expression in a panel of renal carcinoma cell lines with documented relevance to papillary RCC biology [16–18]: Specifically, STK38 was overexpressed in ACHN cells, which exhibit type I pRCC-like features and low endogenous STK38 expression; knocked down in Caki-2 cells, which have been increasingly recognized as molecular surrogates of type II pRCC and express high levels of STK38; and further validated in A498 cells, considered a transcriptionally intermediate subtype bridging clear cell and papillary features.