ABSTRACT Natural Killer cells (NKs), are considered an important first line of defence and were originally defined by their ability to kill certain tumor cells and virally infected cells. Our aim is to study expression of HLA class-Ia on tumor cell lines and their susceptibility of NK cells. In this study MDA-MB-468 tumor cell line (NCB1, C208) That derived from human breast adenocarcino...

most specialists in the field of foreign language teachingconsiderreading skill as an interactive process between the reader’s prior knowledge and the text.accordingly, the activation of prior knowledge for an effective comprehension is very important. it is generally agreed that the pre-reading phase is the stage where this type of interaction and activation may be enhanced throughcertain stra...

the purpose of this study was to investigate the effect of task repetition on accuracy of iranian efl learners ’speaking ability. in order to achieve this purpose, a null hypothesis was developed: there is no statistically significant difference between accuracy speaking ability in iranian efl learners by use of task repetition. ; of course i should mention that, beside this null hypothesis, an...

this study sought to examine the effect of cooperative game on iranian students achievements in english alphabet learning. cooperative games are games, in which players or teams work together towards a common goal without defeating someone. the methodology used in this study was experimental. the population of the study was 60 female students from the grade one in secondary school in tabriz, ir...