ALB and neoplasm with perivascular epithelioid cell differentiation: A new derivative of sirolimus nab-sirolimus (albumin-bound) was recently tested in the single-arm AMPECT study of 31 malignant PEComa patients—nab-sirolimus, an injectable a nanoparticle albumin-bound (nab®) sirolimus with a mean particle size of approximately 100 nm.