SPARC and cancer: Published evidence suggests that four albumin-binding proteins (ABPs) (gp18, gp30, gp60/albondin, and secreted protein acidic and cysteine-rich (SPARC)) could be responsible for the accumulation of small molecule receptor tyrosine kinase inhibitors (RTKIs) in normal organs and tissues and therefore responsible for the side effects and toxicity associated with this type of cancer therapy.