ACTA1 and invasive lobular breast carcinoma: In invasive lobular carcinoma of the breast, in which stromal cells express CD34 or αSMA around neoplastic cells, we demonstrate that (a) stromal cells adopt a similar arrangement and location to resident CD34+SCs/TCs in the normal breast, (b) CD34+ and αSMA+ stromal cells can coincide around the same nest of neoplastic cells and even around a single neoplastic cell and, that c) the stromal cells in the tumour coexpress CD34 and αSMA.